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ORGANIC SPECTROSCOPY

Read all about Organic Spectroscopy on ORGANIC SPECTROSCOPY INTERNATIONAL 

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DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with AFRICURE PHARMA, ROW2TECH, NIPER-G, Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers, Govt. of India as ADVISOR, earlier assignment was with GLENMARK LIFE SCIENCES LTD, as CONSUlTANT, Retired from GLENMARK in Jan2022 Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 32 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 32 PLUS year tenure till date Feb 2023, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 100 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 100 Lakh plus views on dozen plus blogs, 227 countries, 7 continents, He makes himself available to all, contact him on +91 9323115463, email amcrasto@gmail.com, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 38 lakh plus views on New Drug Approvals Blog in 227 countries......https://newdrugapprovals.wordpress.com/ , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc He has total of 32 International and Indian awards

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Pyridostigmine


Pyridostigmine.svg
ChemSpider 2D Image | Pyridostigmine | C9H13N2O2

Pyridostigmine 

  • Molecular FormulaC9H13N2O2
  • Average mass181.211 Da

155-97-5[RN]3-[(Dimethylcarbamoyl)oxy]-1-methylpyridinium
3-Dimethylcarbamoyloxy-1-methyl-pyridinium5-21-02-00078 (Beilstein Handbook Reference)[Beilstein]

Pyridostigmine Bromide

 Pyridostigmine BromideCAS Registry Number: 101-26-8CAS Name: 3-[[(Dimethylamino)carbonyl]oxy]-1-methylpyridinium bromideAdditional Names: 3-hydroxy-1-methylpyridinium bromide dimethylcarbamate; 1-methyl-3-hydroxypyridinium bromide dimethylcarbamate; 3-(dimethylcarbamyloxy)-1-methylpyridinium bromideManufacturers’ Codes: Ro-1-5130Trademarks: Kalymin (Temmler); Mestinon (Roche); Regonol (Organon)Molecular Formula: C9H13BrN2O2Molecular Weight: 261.12Percent Composition: C 41.40%, H 5.02%, Br 30.60%, N 10.73%, O 12.25%Literature References: Reversible inhibitor of acetylcholinesterase. 
Prepn: Urban, US2572579 (1951 to Hoffmann-La Roche). Mechanism of protective effect in soman poisoning: X. Deyi et al.,Fundam. Appl. Toxicol.1, 217 (1981). Evaluation of effect on neuromuscular function: M. Glikson et al.,ibid.16, 288 (1991). Evaluation of side effects profile under desert conditions: J. E. Cook et al.,Mil. Med.157, 250 (1992). Review of prophylactic effect in nerve agent poisoning: R. M. Dawson, J. Appl. Toxicol.14, 317 (1994).Properties: Shiny, hygroscopic crystals from abs ethanol, mp 152-154°. Freely sol in water, alcohol. Practically insol in ether, acetone, benzene. Aq solns may be sterilized by autoclaving with steam.Melting point: mp 152-154°Therap-Cat: Cholinergic; in treatment of myasthenia gravis. Pre-exposure antidote to chemical warfare agents.Keywords: Cholinergic.

Pyridostigmine is a medication used to treat myasthenia gravis.[1] It is also used together with atropine to end the effects of neuromuscular blocking medication of the non-depolarizing type.[2] It is typically given by mouth but can also be used by injection.[2] The effects generally begin within 45 minutes and last up to 6 hours.[2]

Common side effects include nausea, diarrhea, frequent urination, and abdominal pain.[2] More severe side effects include low blood pressure, weakness, and allergic reactions.[2] It is unclear if use in pregnancy is safe for the fetus.[2] Pyridostigmine is an acetylcholinesterase inhibitor in the cholinergic family of medications.[2] It works by blocking the action of acetylcholinesterase and therefore increases the levels of acetylcholine.[2]

Pyridostigmine was patented in 1945 and came into medical use in 1955.[3] It is on the World Health Organization’s List of Essential Medicines.[4] Pyridostigmine is available as a generic medication.[2]

Medical uses

Pyridostigmine is used to treat muscle weakness in people with myasthenia gravis or forms of congenital myasthenic syndrome and to combat the effects of curariform drug toxicity. Pyridostigmine bromide has been FDA approved for military use during combat situations as an agent to be given prior to exposure to the nerve agent Soman in order to increase survival. Used in particular during the first Gulf War, pyridostigmine bromide has been implicated as a causal factor in Gulf War syndrome.[5]

Pyridostigmine sometimes is used to treat orthostatic hypotension.[6] It may also be of benefit in chronic axonal polyneuropathy.[7]

It is also being prescribed ‘off-label’ for the postural tachycardia syndrome as well as complications resulting from Ehlers–Danlos syndrome.[7][8]

Contraindications

Pyridostigmine bromide is contraindicated in cases of mechanical intestinal or urinary obstruction and should be used with caution in patients with bronchial asthma.[9][10]

Side effects

Common side effects include:[9]

  • Sweating
  • Diarrhea
  • Nausea
  • Vomiting
  • Abdominal cramps
  • Increased salivation
  • Tearing
  • Increased bronchial secretions
  • Constricted pupils
  • Facial flushing due to vasodilation
  • Erectile dysfunction

Additional side effects include:[9]

  • Muscle twitching
  • Muscle cramps and weakness

Mechanism of action

Pyridostigmine inhibits acetylcholinesterase in the synaptic cleft, thus slowing down the hydrolysis of acetylcholine. It is a quaternary carbamate inhibitor of cholinesterase that does not cross the blood–brain barrier which carbamylates about 30% of peripheral cholinesterase enzyme. The carbamylated enzyme eventually regenerates by natural hydrolysis and excess ACh levels revert to normal.

The ACh diffuses across the synaptic cleft and binds to receptors on the post synaptic membrane, causing an influx of Na+, resulting in depolarization. If large enough, this depolarization results in an action potential. To prevent constant stimulation once the ACh is released, an enzyme called acetylcholinesterase is present in the endplate membrane close to the receptors on the post synaptic membrane, and quickly hydrolyses ACh.

Names

Pyridostigmine bromide is available under the trade names Mestinon (Valeant Pharmaceuticals), Regonol and Gravitor (SUN Pharma).

Chemistry

Pyridostigmine, 3-[(dimethylaminocarbonyl)oxy]-1-methyl pyridinium bromide, is synthesized from 3-hydroxypyridine, which is reacted with dimethylaminocarbamoyl chloride, which gives 3-(dimethylaminocarbamoyl)pyridine. The last is reacted with methylbromide, giving pyridostigmine.

Syn

youtube

SYN

Method of synthesis

i. 3-hydroxypiridine is reacted with dimethylaminocarbamoyl chloride to give 3-(dimethylaminocarbamoyl)pyridine.

ii. The above formed compound is reacted with methylbromide to produce pyridostigmine. [2]

File:Synthese von Pyridostigmin.svg - Wikimedia Commons

CLIP

Paper

Journal of Biological Chemistry (1961), 236, 1498-500.

 Zeitschrift fuer Klinische Medizin (1985) (1986), 41(7), 495-8

Zhonghua Yaoxue Zazhi (1993), 45(6), 601-14.

Trends in Organic Chemistry (2011), 15, 25-31.

PATENT

WO 9822458

PATENT

WO 2008074816

https://patents.google.com/patent/WO2008074816A1/en

References

  1. ^ World Health Organization (2009). Stuart MC, Kouimtzi M, Hill SR (eds.). WHO Model Formulary 2008. World Health Organization. p. 429. hdl:10665/44053ISBN 9789241547659.
  2. Jump up to:a b c d e f g h i “Neostigmine Bromide”. The American Society of Health-System Pharmacists. Archived from the original on 21 December 2016. Retrieved 8 December 2016.
  3. ^ Fischer, Janos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 540. ISBN 9783527607495Archived from the original on 2016-12-20.
  4. ^ World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  5. ^ Golomb BA (March 2008). “Acetylcholinesterase inhibitors and Gulf War illnesses”Proceedings of the National Academy of Sciences of the United States of America105 (11): 4295–300. Bibcode:2008PNAS..105.4295Gdoi:10.1073/pnas.0711986105JSTOR 25461411PMC 2393741PMID 18332428Lay summary – Reuters (March 10, 2008).
  6. ^ Gales BJ, Gales MA (2007). “Pyridostigmine in the treatment of orthostatic intolerance”. Annals of Pharmacotherapy41 (2): 314–8. doi:10.1345/aph.1H458PMID 17284509S2CID 22855759.
  7. Jump up to:a b Gales BJ, Gales MA (February 2007). “Pyridostigmine in the treatment of orthostatic intolerance”. The Annals of Pharmacotherapy41 (2): 314–8. doi:10.1345/aph.1H458PMID 17284509S2CID 22855759.
  8. ^ Kanjwal K, Karabin B, Sheikh M, et al. (June 2011). “Pyridostigmine in the treatment of postural orthostatic tachycardia: a single-center experience”. Pacing and Clinical Electrophysiology34 (6): 750–5. doi:10.1111/j.1540-8159.2011.03047.xPMID 21410722S2CID 20405336.
  9. Jump up to:a b c Mestinon | Home Archived 2008-05-13 at the Wayback Machine
  10. ^ Mestinon Official FDA information, side effects and uses Archived 2008-05-24 at the Wayback Machine

External links[

Clinical data
Trade namesMestinon, others
AHFS/Drugs.comMonograph
MedlinePlusa682229
Pregnancy
category
AU: C
Routes of
administration
by mouth, intravenous
ATC codeN07AA02 (WHO)
Legal status
Legal statusUK: POM (Prescription only)US: ℞-only
Pharmacokinetic data
Bioavailability7.6 +/- 2.4%
Elimination half-life1.78 +/- 0.24hrs
Excretionkidney
Identifiers
showIUPAC name
CAS Number155-97-5 
PubChem CID4991
DrugBankDB00545 
ChemSpider4817 
UNII19QM69HH21
KEGGD00487 
ChEMBLChEMBL1115 
CompTox Dashboard (EPA)DTXSID20165786 
Chemical and physical data
FormulaC9H13N2O2
Molar mass181.215 g·mol−1
3D model (JSmol)Interactive image
hideSMILESO=C(Oc1ccc[n+](c1)C)N(C)C
hideInChIInChI=1S/C9H13N2O2/c1-10(2)9(12)13-8-5-4-6-11(3)7-8/h4-7H,1-3H3/q+1 Key:RVOLLAQWKVFTGE-UHFFFAOYSA-N 

/////////////Pyridostigmine,

Buspirone


Buspirone 200.svg
Buspirone

Buspirone

  • Molecular FormulaC21H31N5O2
  • Average mass385.503 Da
  • буспиронبوسبيرون丁螺酮

251-489-4[EINECS]253-072-2[EINECS]36505-84-7[RN]8-[4-(4-Pyrimidin-2-yl-piperazin-1-yl)-butyl]-8-aza-spiro[4.5]decane-7,9-dione8-[4-[4-(2-Pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione

  • 8-[4-[4-(2-Pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione
  • Buspin
  • Buspirone
  • Spitomin

BuspironeCAS Registry Number: 36505-84-7CAS Name: 8-[4-[4-(2-Pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dioneMolecular Formula: C21H31N5O2Molecular Weight: 385.50Percent Composition: C 65.43%, H 8.11%, N 18.17%, O 8.30%Literature References: Non-benzodiazepine anxiolytic; 5-hydroxytryptamine (5-HT1) receptor agonist. Prepn: Y. H. Wu et al.,J. Med. Chem.15, 477 (1972); Y. H. Wu, J. W. Rayburn, DE2057845 (1971 to Bristol-Myers); eidem,US3717634 (1973 to Mead-Johnson). Pharmacology: L. E. Allen et al.,Arzneim.-Forsch.24, 917 (1974). Comparison with diazepam in treatment of anxiety: H. L. Goldberg, R. J. Finnerty, Am. J. Psychiatry136, 1184 (1979); A. F. Jacobson et al.,Pharmacotherapy5, 290 (1985). Nonsynergistic effect with alcohol: T. Seppala et al.,Clin. Pharmacol. Ther.32, 201 (1982). Disposition and metabolism: S. Caccia et al.,Xenobiotica13, 147 (1983). Series of articles on chemistry, pharmacology, addictive potential, and clinical trials: J. Clin. Psychiatry43, pp 1-116 (1982); on pharmacology, safety and clinical comparison with clorazepate: Am. J. Med.80, Suppl. 3B, 1-51 (1986). Review of pharmacology and therapeutic efficacy: K. L. Goa, A. Ward, Drugs32, 114-129 (1986). Review: M. W. Jann, Pharmacotherapy8, 100-116 (1988); D. P. Taylor, FASEB J.2, 2445-2452 (1988). 
Derivative Type: HydrochlorideCAS Registry Number: 33386-08-2Trademarks: Ansial (Vita); Ansiced (Abello); Axoren (Glaxo Wellcome); Bespar (BMS); Buspar (BMS); Buspimen (Menarini); Buspinol (Zdravlje); Buspisal (Lesvi); Narol (Almirall)Molecular Formula: C21H31N5O2.HClMolecular Weight: 421.96Percent Composition: C 59.77%, H 7.64%, N 16.60%, O 7.58%, Cl 8.40%Properties: Crystals from abs ethanol, mp 201.5-202.5°. LD50 i.p. in rats: 136 mg/kg (Allen).Melting point: mp 201.5-202.5°Toxicity data: LD50 i.p. in rats: 136 mg/kg (Allen) 
Therap-Cat: Anxiolytic.Keywords: Anxiolytic; Arylpiperazines; Serotonin Receptor Agonist.

Buspirone, sold under the brand name Buspar, among others, is a medication primarily used to treat anxiety disorders, particularly generalized anxiety disorder.[9][10] Benefits support its short term use.[11] It has not been found to be effective in treating psychosis.[9] It is taken by mouth, and it may take up to four weeks to have an effect.[9][10]

Common side effects of buspirone include nausea, headaches, dizziness, and difficulty concentrating.[9][11] Serious side effects may include hallucinationsserotonin syndrome, and seizures.[11] Its use in pregnancy appears to be safe but has not been well studied, while use during breastfeeding is not recommended.[11][12] It is a serotonin 5-HT1A receptor agonist.[2]

Buspirone was first made in 1968 and approved for medical use in the United States in 1986.[9][10] It is available as a generic medication.[11] In 2018, it was the 92nd most-commonly prescribed medication in the United States, with more than 8 million prescriptions.[13][14]

Medical uses

Anxiety

Buspirone is used for the short-term treatment of anxiety disorders or symptoms of anxiety.[15][16][17][18][19] It is generally less preferred than selective serotonin reuptake inhibitors (SSRIs).[10]

Buspirone has no immediate anxiolytic effects, and hence has a delayed onset of action; its full clinical effectiveness may require 2–4 weeks to manifest itself.[20] The drug has been shown to be similarly effective in the treatment of generalized anxiety disorder (GAD) to benzodiazepines including diazepamalprazolamlorazepam, and clorazepate.[2] Buspirone is not known to be effective in the treatment of other anxiety disorders besides GAD,[21] although there is some limited evidence that it may be useful in the treatment of social phobia as an adjunct to selective serotonin reuptake inhibitors (SSRIs).[2][22]

Other uses

Sexual dysfunction

There is some evidence that buspirone on its own may be useful in the treatment of hypoactive sexual desire disorder (HSDD) in women.[23]

Miscellaneous

Buspirone is not effective as a treatment for benzodiazepine withdrawalbarbiturate withdrawal, or alcohol withdrawal/delirium tremens.[24]

SSRI and SNRI antidepressants such as paroxetine and venlafaxine may cause jaw pain/jaw spasm reversible syndrome (although it is not common), and buspirone appears to be successful in treating bruxism on SSRI/SNRI-induced jaw clenching.[25][26]

Contraindications

Buspirone has these contraindications:[27][28]

Side effects

Main article: List of side effects of buspirone

Known side effects associated with buspirone include dizzinessheadachesnauseanervousness, and paresthesia.[2] Buspirone is relatively well tolerated, and is not associated with sedationcognitive and psychomotor impairmentmuscle relaxationphysical dependence, or anticonvulsant effects.[2] In addition, buspirone does not produce euphoria[20] and is not a drug of abuse.[16]

It is unclear if there is a risk of tardive dyskinesia or other movement disorders with buspirone.[9]

Overdose

Buspirone appears to be relatively benign in cases of single-drug overdose, although no definitive data on this subject appear to be available.[29] In one clinical trial, buspirone was administered to healthy male volunteers at a dosage of 375 mg/day, and produced side effects including nauseavomitingdizzinessdrowsinessmiosis, and gastric distress.[15][16][18] In early clinical trials, buspirone was given at dosages even as high as 2,400 mg/day, with akathisiatremor, and muscle rigidity observed.[30] Deliberate overdoses with 250 mg and up to 300 mg buspirone have resulted in drowsiness in about 50% of individuals.[30] One death has been reported in association with 450 mg buspirone together with alprazolamdiltiazemalcoholcocaine.[30]

Interactions

Buspirone has been shown in vitro to be metabolized by the enzyme CYP3A4.[8] This finding is consistent with the in vivo interactions observed between buspirone and these inhibitors or inducers of cytochrome P450 3A4 (CYP3A4), among others:[27]

Elevated blood pressure has been reported when buspirone has been administered to patients taking monoamine oxidase inhibitors (MAOIs).[27]

Pharmacology

Pharmacodynamics

SiteKi (nM)SpeciesRef
5-HT1A3.98–214
21 (median)
Human[33][34]
5-HT1B>100,000Rat[35]
5-HT1D22,000–42,700Human[36][37]
5-HT2A138
759–1,300
Human
Rat
[38]
[35][38]
5-HT2B214Human[38]
5-HT2C490
1,100–6,026
Human
Rat/pig
[38]
[35][38]
5-HT3>10,000Rat[39][40]
5-HT4>10,000Rat[40]
5-HT6398Mouse[41]
5-HT7375–381Rat[42][43]
α11,000Rat[35]
α26,000Rat[44]
α2A7.3 (1-PP)Human[35]
β8,800Rat[35]
D133,000Rat[35]
D2484
240
Human
Rat
[45]
[35]
D398Human[45]
D429Human[45]
mACh38,000Rat[35]
GABAA
(BDZ)
>100,000Rat[35]
Values are Ki (nM). The smaller the value, the more strongly the drug binds to the site.

Buspirone acts as an agonist of the serotonin 5-HT1A receptor with high affinity.[2][35] It is a partial agonist of both presynaptic 5-HT1A receptors, which are inhibitory autoreceptors, and postsynaptic 5-HT1A receptors.[2] It is thought that the main effects of buspirone are mediated via its interaction with the presynaptic 5-HT1A receptor, thus reducing the firing of serotonin-producing neurons.[2] Buspirone also has lower affinities for the serotonin 5-HT2A5-HT2B5-HT2C5-HT6, and 5-HT7 receptors.[33]

In addition to binding to serotonin receptors, buspirone is an antagonist of the dopamine D2 receptor with weak affinity.[2][35] It preferentially blocks inhibitory presynaptic D2 autoreceptors, and antagonizes postsynaptic D2 receptors only at higher doses.[2] In accordance, buspirone has been found to increase dopaminergic neurotransmission in the nigrostriatal pathway at low doses, whereas at higher doses, postsynaptic D2 receptors are blocked and antidopaminergic effects such as hypoactivity and reduced stereotypy, though notably not catalepsy, are observed in animals.[2] Buspirone has also been found to bind with much higher affinity to the dopamine D3 and D4 receptors, where it is similarly an antagonist.[45]

A major metabolite of buspirone, 1-(2-pyrimidinyl)piperazine (1-PP), occurs at higher circulating levels than buspirone itself and is known to act as a potent α2-adrenergic receptor antagonist.[44][46][47] This metabolite may be responsible for the increased noradrenergic and dopaminergic activity observed with buspirone in animals.[46][48] In addition, 1-PP may play an important role in the antidepressant effects of buspirone.[48] Buspirone also has very weak and probably clinically unimportant affinity for the α1-adrenergic receptor.[35][49] However, buspirone has been reported to have shown “significant and selective intrinsic efficacy” at the α1-adrenergic receptor expressed in a “tissue- and species-dependent manner”.[49]

Unlike benzodiazepines, buspirone does not interact with the GABAA receptor complex.[2][50]

Pharmacokinetics

Buspirone has a low oral bioavailability of 3.9% relative to intravenous injection due to extensive first-pass metabolism.[2] The time to peak plasma levels following ingestion is 0.9 to 1.5 hours.[2] It is reported to have an elimination half-life of 2.8 hours,[2] although a review of 14 studies found that the mean terminal half-life ranged between 2 and 11 hours, and one study even reported a terminal half-life of 33 hours.[4] Buspirone is metabolized primarily by CYP3A4, and prominent drug interactions with inhibitors and inducers of this enzyme have been observed.[7][8] Major metabolites of buspirone include 5-hydroxybuspirone, 6-hydroxybuspirone, 8-hydroxybuspirone, and 1-PP.[4][5][6] 6-Hydroxybuspirone has been identified as the predominant hepatic metabolite of buspirone, with plasma levels that are 40-fold greater than those of buspirone after oral administration of buspirone to humans.[5] The metabolite is a high-affinity partial agonist of the 5-HT1A receptor (Ki = 25 nM) similarly to buspirone, and has demonstrated occupancy of the 5-HT1A receptor in vivo.[5] As such, it is likely to play an important role in the therapeutic effects of buspirone.[5] 1-PP has also been found to circulate at higher levels than those of buspirone itself and may similarly play a significant role in the clinical effects of buspirone.[46][48]

Phase I Metabolism of buspirone in humans[51][52][8]

History

Buspirone was first synthesized, by a team at Mead Johnson, in 1968,[21] but was not patented until 1975.[54][55] It was initially developed as an antipsychotic drug acting on the D2 receptor, but was found to be ineffective in the treatment of psychosis; it was then used as an anxiolytic instead.[2] In 1986, Bristol-Myers Squibb gained FDA approval for buspirone in the treatment of GAD.[21][56] The patent placed on buspirone expired in 2001 and it is now available as a generic drug.

Society and culture

Buspar (buspirone) 10-mg tablets

Generic names

Buspirone is the INNBANDCF, and DCIT of buspirone, while buspirone hydrochloride is its USANBANM, and JAN.[1][57][58][59]

Brand name

Buspirone was primarily sold under the brand name Buspar.[57][59] Buspar is currently listed as discontinued by the US Federal Drug Administration.[60] In 2010, in response to a citizen petition, the US FDA determined that Buspar was not withdrawn for sale because of reasons of safety or effectiveness.[61]

2019 shortage

Due to interrupted production at a Mylan Pharmaceuticals plant in Morgantown, West Virginia, the United States experienced a shortage of buspirone in 2019.[62]

Research

Some tentative research supports other uses such as the treatment of depression and behavioral problems following brain damage.[2]

Chemistry

Buspirone is a member of the azapirone chemical class, and consists of azaspirodecanedione and pyrimidinylpiperazine components linked together by a butyl chain.

Analogues

Structural analogues of buspirone include other azapirones like gepironeipsapironeperospirone, and tandospirone.[53]

Synthesis

Buspirone synthesis:[54] DE 2057845 U.S. Patent 3,717,634 U.S. Patent 3,907,801 U.S. Patent 3,976,776

Alkylation of 1-(2-pyrimidyl)piperazine (1) with 3-chloro-1-cyanopropane (2, 4-chlorobutyronitrile) gives 3, which is reduced either by hydrogenation over Raney nickel catalyst, or with LAH. The resulting 1° amine (4) from the previous step is then reacted with 3,3-tetramethyleneglutaric anhydride (5, 8-Oxaspiro[4.5]decane-7,9-dione) in order to yield buspirone (6).

PAPERS

  1. Koziol, Anna E.; Acta Crystallographica, Section E: Structure Reports Online 2006, V62(12), Po5616-o5618 
  2. Mou, Jie; Organic Preparations and Procedures International 2008, V40(4), P391-394 
  3. Kairisalo, Pekka Juhani; FI 72975 B 1987 
  4. Journal of medicinal chemistry (1983), 26(2), 194-203
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PAPER

https://pubs.rsc.org/en/content/articlelanding/2019/GC/C8GC03328E#!divAbstract

  1. Green Chemistry, 21(1), 59-63; 2019

Abstract

A continuous flow method for the direct conversion of alcohols to amines via a hydrogen borrowing approach is reported. The method utilises a low loading (0.5%) of a commercial catalyst system ([Ru(p-cymene)Cl2]2 and DPEPhos), reagent grade solvent and is selective for primary alcohols. Successful methylation of amines using methanol and the direct dimethylamination of alcohols using commercial dimethylamine solution are reported. The synthesis of two pharmaceutical agents Piribedil (5) and Buspirone (25) were accomplished in good yields employing these new methods.

Graphical abstract: Fast continuous alcohol amination employing a hydrogen borrowing protocol

http://www.rsc.org/suppdata/c8/gc/c8gc03328e/c8gc03328e2.pdf
8-(4-hydroxybutyl)-8-azaspiro[4.5]decane-7,9-dione (23): A solution of 3,3-tetramethyleneglutaric anhydride (0.25 mol/L in THF) was combined in a tee piece with a solution of 4-amino-1-butanol (0.25 mol/L in THF) and reacted in a 20 mL reactor coil (stainless steel, 20 min residence time) heated at 250 °C. The output was concentrated in vacuo and the residue purified by column chromatography on silica gel to afford the product in 84% yield (Rf = 0.31, 63% DCM/AcOEt). 1H NMR (400 MHz, CDCl3) δ = 3.78 (t, J = 7.2 Hz, 2H), 3.65 (t, J = 6.0 Hz, 2H), 2.58 (s, 4H), 1.77 – 1.64 (m, 4H), 1.64 – 1.53 (m, 4H), 1.53 – 1.43 (m, 4H). 13C NMR (100 MHz, CDCl3) δ = 172.33, 62.28, 44.87, 39.47, 39.14, 37.54, 29.81, 24.35, 24.17. HRMS for [C13H22NO3] + calculated 240.1594 found 240.1605. 

8-(4-(4-(pyrimidin-2-yl)piperazin-1-yl)butyl)-8-azaspiro[4.5]decane-7,9-dione (Buspirone, 25): The flow system was flushed with THF, the back-pressure regulator was set to 50 bar, and the coil reactor heated to 250 °C. Then a solution (10 mL overall volume) containing 1-(2-pyrimidyl)piperazine (2 mmol), 8-(4-hydroxybutyl)- 8-azaspiro[4.5]decane-7,9-dione (23) (2 mmol), dichloro(p-cymene)ruthenium(II) dimer (0.08 mmol) and bis[(2- diphenylphosphino)phenyl] ether (DPEPhos, 0.17 mmol) was pumped at 0.8 ml/min through a heated coil (8 mL, Phoenix reactor). The output solution obtained in steady state (monitored using the FlowUV) was concentrated in vacuo and purified by column chromatography on silica gel to afford the desired product in 76% yield (Rf = 0.29, 5% MeOH/DCM). 1H NMR (400 MHz, CDCl3) δ = 8.31 (d, J = 4.7 Hz, 2H), 6.48 (t, J = 4.7 Hz, 1H), 3.84 (t, J = 5.1 Hz, 4H), 3.79 (t, J = 6.8 Hz, 2H), 2.60 (s, 4H), 2.50 (t, J = 5.1 Hz, 4H), 2.40 (t, J = 6.8 Hz, 2H), 1.79 – 1.65 (m, 4H), 1.65 – 1.42 (m, 8H). 13C NMR (100 MHz, CDCl3) δ = 172.19, 161.63, 157.68, 109.77, 58.31, 53.06, 44.92, 43.60, 39.48, 39.35, 37.56, 26.04, 24.19, 24.19. HRMS for [C21H32N5O2] + calculated 386.2551 found 386.2570.

PAPER

Organic Preparations and Procedures International, 40(4), 391-394; 2008

https://www.tandfonline.com/doi/abs/10.1080/00304940809458099

PATENTS

US 3907801

ES 526304

EP 395192

EP 565274

EP 634411

EP 680961

US 5521313

Indian Pat. Appl., 2011MU01860,

PATENTS

WO 2014152737

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2014152737

Syn

J Med Chem 1972,15(5),477-479

DE 2057845; FR 2073406; GB 1332194; US 3717634

The condensation of 1-(2-pyrimidinyl)piperazine (I) with 3-chloro-1-cyanopropane (II) by means of Na2CO3 in n-butanol gives 4-(2-pyrimidinyl)-1-(3-cyanopropyl)piperazine (III). This product is reduced with LiAlH4 or with H2 and Raney-Ni yielding 4-(2-pyrimidinyl)-1-(4-aminobutyl)piperazine (IV), which is finally condensed with 8-oxaspiro[4.5]decane-7,9-dione-(3,3-tetramethylene-glutaric anhydride) (V) in pyridine.

CLIP

Anxiolytics (Tranquilizers)

R.S. Vardanyan, V.J. Hruby, in Synthesis of Essential Drugs, 2006

Buspirone

Buspirone, 8-[4-[4-(2-pyrimidyl)-1-piperazinyl]butyl]-8-azaspiro [4,5] decan-7,9-dione (5.2.6), is synthesized by the reaction of 1-(2-pyrimidyl)-4-(4-aminobutyl)piperazine (5.2.4) with 8-oxaspiro[4,5]decan-7,9-dione (5.2.5). In turn, 1-(2-pyrimidyl)-4-(4-aminobutyl)piperazine (5.2.4) is synthesized by the reaction of 1-(2-pyrimidyl)piperazine with 4-chlorobutyronitrile, giving 4-(2-pyrimidyl)-1-(3-cyanopropyl)piperazine (5.2.3), which is hydrogenated with Raney nickel into buspirone (5.2.4) [51–55].

Buspirone is an extremely specific drug that could possibly represent a new chemical class of anxiolytics—azaspirones. As an anxiolytic, its activity is equal to that of benzodiazepines; however, it is devoid of anticonvulsant and muscle relaxant properties, which are characteristic of benzodiazepines. It does not cause dependence or addiction. The mechanism of its action is not conclusively known. It does not act on the GABA receptors, which occurs in benzodiazepine use; however, it has a high affinity for seratonin (5-HT) receptors and a moderate affinity for dopamine (D2) receptors. Buspirone is effective as an anxiolytic. A few side effects of buspirone include dizziness, drowsiness, headaches, nervousness, fatigue, and weakness. This drug is intended for treatment of conditions of anxiety in which stress, muscle pain, rapid heart rate, dizziness, fear, etc. are observed; in other words, conditions of anxiety not associated with somewhat common, usual, and everyday stress. Synonyms for buspirone are anizal, axoren, buspar, buspimen, buspinol, narol, travin, and others.

CLIP

Applications of Biocatalysis for Pharmaceuticals and Chemicals

Ramesh N. Patel, in Organic Synthesis Using Biocatalysis, 2016

5.2 Enzymatic Preparation of 6-Hydroxybuspirone

Buspirone (Buspar®59, Figure 11.17) is a drug used for the treatment of anxiety and depression, thought to produce its effects by binding to the serotonin 5HT1A receptor [114–116]. Mainly as a result of hydroxylation reactions, it is extensively converted to various metabolites and blood concentrations return to low levels a few hours after dosing [117]. A major metabolite, 6-hydroxybuspirone, produced by the action of liver cytochrome P450 CYP3A4, was present at much higher concentrations in human blood than buspirone itself. For development of 6-hydroxybuspirone as a potential antianxiety drug, preparation and testing of the two enantiomers as well as the racemate was of interest. An enantioselective microbial reduction process was developed for the reduction of 6-oxobuspirone 60 to (R)-6-hydroxybuspirone 61a or (S)-6-hydroxybuspitone 61b. About 150 microbial cultures were screened for the enantioselective reduction of 60Rhizopus stolonifer SC 13898, Neurospora crassa SC 13816, Mucor racemosus SC 16198, and Pseudomonas putida SC 13817 gave >50% reaction yields and >95% ee of (S)-6-hydroxybuspirone 61a. The yeast strains Hansenula polymorpha SC 13845 and Candida maltosa SC 16112 gave (R)-6-hydroxybuspirone in >60% reaction yield and >97% ee [118]. The NADPH-dependent (R)-reductase (RHBR) from H. polymorpha SC 13845 was purified to homogeneity, its N-terminal and internal amino acid sequences were determined and the corresponding gene was cloned and expressed in E. coli. To regenerate the NADPH required for reduction, glucose-6-phosphate dehydrogenase gene from Saccharomyces cerevisiae was cloned and coexpressed in the same E. coli strain. Recombinant cultures coexpressing (R)-reductase (RHBR) and glucose 6-phosphate dehydrogenase catalyzed the reduction of 6-ketobuspirone to (R)-6-hydroxybuspirone 61a in 99% yield and 99.9% ee at 50 g/L substrate input [119].

The NADH-dependent (S)-reductase (SHBR) from P. putida SC 16269 was also purified to homogeneity, its N-terminal and internal amino acid sequences were determined and the corresponding gene was cloned and expressed in E. coli. To regenerate the NADH required for reduction, the NAD+ dependent formate dehydrogenase gene from Pichia pastoris was also cloned and co-expressed in the same E. coli strain. Recombinant E. coli coexpressing (S)-reductase and formate dehydrogenase was used to catalyze the reduction of 6-ketobuspirone to (S)-6-hydroxybuspirone 61b, in >98% yield and >99.8% ee at 50 g/L substrate input [119].

PATENT

https://patents.google.com/patent/US6686361

The present invention relates to methods of treating anxiety and depression using R-6-hydroxy-buspirone and pharmaceutical compositions containing R-6-hydroxy-buspirone.

Buspirone, chemically: 8-[4-[4-(2-pyrimidinyl)1-piperazinyl]butyl-8-azaspiro(4,5)-decane-7,9-dione, is approved for the treatment of anxiety disorders and depression by the United States Food and Drug Administration. It is available under the trade name BUSPAR® from Bristol-Myers Squibb Company.

Studies have shown that buspirone is extensively metabolized in the body. (See, for example, Mayol, et al., Clin. Pharmacol. Ther., 37, p. 210, 1985). One of the metabolites is 6-hydroxy-8-[4-[4-(2-pyrimidinyl)1-piperazinyl]butyl-8-azaspiro(4,5)-decane-7,9-dione having Formula I. This metabolite is also known as BMS 28674, BMS 442608, or

Figure US06686361-20040203-C00001

as 6-hydroxy-buspirone. This compound is believed to be the active metabolite of buspirone and its use in treating anxiety disorders and depression is disclosed in U.S. Pat. No. 6,150,365. The specific stereochemistry of 6-hydroxy-buspirone has not been described previously. Neither racemic 6-hydroxy-buspirone nor its enantiomers are commercially available at the present time.

Preclinical studies demonstrate that 6-hydroxy-buspirone, like buspirone, demonstrates a strong affinity for the human 5-HT1A receptor. In functional testing, 6-hydroxy-buspirone produced a dose-dependent anxiolytic response in the rat pup ultrasonic vocalization test, a sensitive method for assessment of anxiolytic and anxiogenic effects (Winslow and Insel, 1991, Psychopharmacology, 105:513-520).

Clinical studies in volunteers orally dosed with buspirone demonstrate that 6-hydroxy-buspirone blood plasma levels were not only 30 to 40 times higher but were sustained compared to buspirone blood plasma levels. The time course of 6-hydroxy-buspirone blood plasma levels, unlike buspirone blood plasma levels, correlate more closely with the sustained anxiolytic effect seen following once or twice a day oral dosing with buspirone.

Although buspirone is an effective treatment for anxiety disorders and depression symptomatology in a significant number of patients treated, about a third of patients get little to no relief from their anxiety and responders often require a week or more of buspirone treatment before experiencing relief from their anxiety symptomatology. Further, certain adverse effects are reported across the patient population. The most commonly observed adverse effects associated with the use of buspirone include dizziness, nausea, headache, nervousness, lightheadedness, and excitement. Also, since buspirone can bind to central dopamine receptors, concern has been raised about its potential to cause unwanted changes in dopamine-mediated neurological functions and a syndrome of restlessness, appearing shortly after initiation of oral buspirone treatment, has been reported in small numbers of patients. While buspirone lacks the prominent sedative effects seen in more typical anxiolytics such as the benzodiazepines, patients are nonetheless advised against operating potentially dangerous machinery until they experience how they are affected by buspirone.

It can be seen that it is desirable to find a medicament with buspirone’s advantages but which demonstrates more robust anxiolytic potency with a lack of the above described adverse effects.

Formation of 6-hydroxy-buspirone occurs in the liver by action of enzymes of the P450 system, specifically CYP3A4. Many substances such as grapefruit juice and certain other drugs; e.g. erythromycin, ketoconazole, cimetidine, etc., are inhibitors of the CYP3A4 isozyme and may interfere with the formation of this active metabolite from buspirone. For this reason it would be desirable to find a compound with the advantages of buspirone but without the drug—drug interactions when coadministered with agents affecting the activity level of the CYP3A4 isozyme.

EXAMPLE 3One-Step Synthesis of 6-Hydroxy-buspirone (I)

Buspirone (19.3 g, 50 mmole) was dissolved in dry THF (400 mL) and the resulting solution was cooled to −78° C. A solution of KN(SiMe3)in toluene (100 mL, 1 M) was added slowly. After the reaction mixture was stirred at −78° C. for 1 h, a solution of 2-(phenylsulfonyl)-3-phenyloxaziridine (Davis reagent, prepared according to literature method: F. A. Davis, et al., Org. Synth., 1988, 66, 203) (17.0 g, 65 mmole) in dry THF (150 mL, precooled to −78° C.) was added quickly via a cannular. After stirred for 30 mins at −78° C., the reaction was quenched with 1 N HCl solution (500 mL). It was extracted with EtOAc (3×500 mL). The aqueous layer was separated, neutralized with saturated sodium bicarbonate solution, and extracted with EtOAc (3×500 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure to give a white solid residue which was subjected to column chromatography using CH2Cl2/MeOH/NH4OH (200:10:1) as the eluent to give pure 6-hydroxy-buspirone (I, 7.2 g) and a mixture of buspirone and 6-hydroxy-buspirone (I). The mixture was purified by above column chromatography to afford another 3.3 g of pure 6-hydroxy-buspirone (I).

1H NMR (CDCl3) δ8.30 (d, J=4.7 Hz, 2H), 6.48 (t, J=4.7 Hz, 1H), 4.20 (s, 1H), 3.83-3.72 (m, 5H), 3.55 (s, 1H), 2.80 (d, J=17.5 Hz, 1H), 2.55-2.40 (m, 7H), 2.09-2.03 (m, 1H), 1.76-1.54 (m, 10 H), 1.41-1.36 (m, 1H), 1.23-1.20 (m, 1H).

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  48. Jump up to:a b c Fava M (2007). “The combination of buspirone and bupropion in the treatment of depression”. Psychotherapy and Psychosomatics76 (5): 311–2. doi:10.1159/000104708PMID 17700052S2CID 46284917.
  49. Jump up to:a b Stern TA, Fava M, Wilens TE, Rosenbaum JF (27 April 2015). Massachusetts General Hospital Psychopharmacology and Neurotherapeutics E-Book. Elsevier Health Sciences. pp. 29–. ISBN 978-0-323-41323-7.
  50. ^ Nutt DJ, Ballenger JC (15 April 2008). Anxiety Disorders. John Wiley & Sons. pp. 395–. ISBN 978-0-470-98683-7.
  51. ^ Dockens RC, Salazar DE, Fulmor IE, Wehling M, Arnold ME, Croop R (November 2006). “Pharmacokinetics of a newly identified active metabolite of buspirone after administration of buspirone over its therapeutic dose range”. Journal of Clinical Pharmacology46(11): 1308–12. doi:10.1177/0091270006292250PMID 17050795.
  52. ^ Jajoo HK, Mayol RF, LaBudde JA, Blair IA (1989). “Metabolism of the antianxiety drug buspirone in human subjects”. Drug Metabolism and Disposition17 (6): 634–40. PMID 2575499.
  53. ^ Taylor DP, Moon SL (July 1991). “Buspirone and related compounds as alternative anxiolytics”. Neuropeptides. 19 Suppl: 15–9. doi:10.1016/0143-4179(91)90078-wPMID 1679210S2CID 13730683.
  54. Jump up to:a b Allen LE, Ferguson HC, Kissel JW (May 1972). “Psychosedative agents. 2. 8-(4-Substituted 1-piperazinylalkyl)-8-azaspiro(4.5)decane-7,9-diones”. Journal of Medicinal Chemistry15 (5): 477–9. doi:10.1021/jm00275a009PMID 5035267.
  55. ^ US Patent 3907801 N-(8 (4-pyridyl-piperazino)-alkyl(9 -azaspiroalkanediones
  56. ^ United States Federal Drug Administration (September 9, 1986). Approval Type-1 New Molecular Entry.https://www.accessdata.fda.gov/drugsatfda_docs/nda/pre96/018731Orig1s000rev.pdf
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  61. ^ “Determination That BUSPAR (Buspirone Hydrochloride) Tablets, 10 Milligrams, 15 Milligrams, and 30 Milligrams, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness”Federal Register. 2010-10-19. Retrieved 2019-09-20.
  62. ^ Rabin RC (2019-02-01). “Shortage of Anxiety Drug Leaves Patients Scrambling”The New York TimesISSN 0362-4331. Retrieved 2019-09-20.

External links

  •  Media related to Buspirone at Wikimedia Commons
  • “Buspirone”Drug Information Portal. U.S. National Library of Medicine.
Clinical data
Pronunciation/ˈbjuːspɪroʊn/ (BEW-spi-rohn)
Trade namesBuspar, Namanspin
Other namesMJ 9022-1[1]
AHFS/Drugs.comMonograph
MedlinePlusa688005
Pregnancy
category
AU: B1
Routes of
administration
By mouth
ATC codeN05BE01 (WHO)
Legal status
Legal statusAU: S4 (Prescription only)CA℞-onlyUK: POM (Prescription only)US: ℞-only
Pharmacokinetic data
Bioavailability3.9%[2]
Protein binding86–95%[3]
MetabolismLiver (via CYP3A4)[7][8]
Metabolites5-OH-Buspirone; 6-OH-Buspirone; 8-OH-Buspirone; 1-PP[4][5][6]
Elimination half-life2.5 hours[7]
ExcretionUrine: 29–63%[3]
Feces: 18–38%[3]
Identifiers
showIUPAC name
CAS Number36505-84-7 
33386-08-2 (hydrochloride)
PubChem CID2477
IUPHAR/BPS36
DrugBankDB00490 
ChemSpider2383 
UNIITK65WKS8HL
KEGGD07593 
ChEBICHEBI:3223 
ChEMBLChEMBL49 
CompTox Dashboard (EPA)DTXSID2022707 
ECHA InfoCard100.048.232 
Chemical and physical data
FormulaC21H31N5O2
Molar mass385.512 g·mol−1
3D model (JSmol)Interactive image
hideSMILESO=C1N(CCCCN2CCN(CC2)C3=NC=CC=N3)C(CC4(CCCC4)C1)=O
hideInChIInChI=1S/C21H31N5O2/c27-18-16-21(6-1-2-7-21)17-19(28)26(18)11-4-3-10-24-12-14-25(15-13-24)20-22-8-5-9-23-20/h5,8-9H,1-4,6-7,10-17H2 Key:QWCRAEMEVRGPNT-UHFFFAOYSA-N 

////////////Buspirone, буспирон , بوسبيرون , 丁螺酮 , Anxiolytic,Arylpiperazines,  Serotonin Receptor Agonist, Ansial, Vita,  Ansiced,  Abello,  Axoren, Glaxo Wellcome,  Bespar, BMS,  Buspar, Buspimen, Menarini,  Buspinol, Zdravlje,  Buspisal, Lesvi,  Narol, Almirall,

#Buspirone, #буспирон , #بوسبيرون , #丁螺酮 , #Anxiolytic, #Arylpiperazines,  #Serotonin Receptor Agonist, #Ansial, #Vita,  #Ansiced,  #Abello,  #Axoren, #Glaxo Wellcome,  #Bespar, #BMS,  #Buspar, #Buspimen, Menarini,  Buspinol, Zdravlje,  Buspisal, Lesvi,  Narol, Almirall,

Azelnidipine


Azelnidipine structure.svg
Azelnidipine.png

Azelnidipine

C33H34N4O6, 582.6 g/mol

CAS 123524-52-7

3-(1-Benzhydrylazetidin-3-yl) 5-isopropyl 2-amino-6-methyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate

CS-905, RS-9054

3,5-PYRIDINEDICARBOXYLIC ACID, 2-AMINO-1,4-DIHYDRO-6-METHYL-4-(3-NITROPHENYL)-, 3-[1-(DIPHENYLMETHYL)-3-AZETIDINYL] 5-(1-METHYLETHYL) ESTER

Approved India cdsco 2020

SYN REF https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4245158/

MP 95-98 °C AND NMR WO 2004058745 . EP 266922 

Azelnidipine is a dihydropyridine calcium channel blocker. It is marketed by Daiichi-Sankyo pharmaceuticals, Inc. in Japan. It has a gradual onset of action and produces a long-lasting decrease in blood pressure, with only a small increase in heart rate, unlike some other calcium channel blockers. It is currently being studied for post-ischemic stroke management.

Azelnidipine (INN; marketed under the brand name CalBlock — カルブロック) is a dihydropyridine calcium channel blocker. Azelnidipine is L and T calcium channel blocker. It is sold in Japan by Daiichi-Sankyo pharmaceuticals, Inc. Unlike nicardipine, it has a gradual onset and has a long-lasting hypotensive effect, with little increase in heart rate. Drug Controller General Of India (DCGI) has approved the use of azelnipine in India. It is launched under the brand name Azusa (ajanta pharma ltd.)[1] In 2020.

Chemical Synthesis

A solution of benzhydrylamine (46) and epichlorohydrin (47) was mixed without adding solvent to give azetidinol 48 in 57% yield. DCC coupling between cyanoacetic acid (49) and azetidinol 48 in hot THF gave ester 50 in 93% yield. Cyanoester 50 was treated with ethanol and HCl gas in chloroform to give imidate HCl salt 51, which was treated with ammonia gas in chloroform and ammonium acetate in acetonitrile to give the corresponding amidinoacetate 52. A modified Hantzsch reaction was employed to construct the 2-amino-1,4- dihydropyridine core structure. Compound 52 was condensed with 2-(3-nitrobenzylidene)acetic acid isopropyl ester (55) in the presence of NaOMe in refluxing isopropanol to give the cyclized product, azelnidipine (V) in 74% yield. Benzylideneacetoacetate 55 was obtained through the Knoevenagel reaction employing 3-nitrobenzaldehyde (53) and isopropyl acetoacetate (54) in isopropanol containing a catalytic amount of piperidinium acetate at 45-55oC in 65% yield.

PATENT

EP 266922 

IN 201621044802 

CN 106279109 

CN 107188885

CN 105461691

CN 103509003 

CN 103183663

CN 102382104 

JP 2012020970 A

PAPER

Bioanalysis (2019), 11(4), 251-266.

PAPER

Asian Journal of Chemistry (2014), 26(15), 4675-4678.

PAPER

http://www.asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=26_16_30

Azelnidipine is designated chemically as 3-(1-benzhydrylazetidin-3-yl)-5-isopropyl-2-amino-6-methyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate. Its literature synthesis (Scheme-I) involves 3-nitrobenzaldehyde 5 with isopropyl acetoacetate 6. The product of (Z)-isopropyl 2-(3- nitrobenzylidene)-3-oxobutanoate (7a, b, c), on treatment with piperidine and acetic acid, coupling of (7) and 1-benzhydrylazetidin-3-yl 3-amino-3-iminopropanoate acetate (8) gave azelnidipine (1).

PAPER

International Research Journal of Pharmacy (2012), 3(8), 191-192.  

Chemical & Pharmaceutical Bulletin (1995), 43(5), 797-817. 

PATENT

https://patents.google.com/patent/WO2014139410A1/en

The invention belongs to the technical field of medicine and provides an important intermediate of dihydropyridine calcium antagonist adipine, 3-amino-3-iminopropionic acid-1-(diphenylhydrazinyl)-3-azetidine The synthesis process of ester acetate. Background technique

 Azelnidipine is a new type of dihydropyridine calcium channel blocker developed by Sankyo and Ube Industries of Japan. It was approved for sale in Japan in late May 2003 under the trade name Calblock. Adipine has a selective blockade of calcium channels in arterial smooth muscle cells, it can dilate blood vessels, reduce peripheral vascular resistance and arterial pressure, and is widely used clinically for mild or moderate essential hypertension, renal disorders with hypertension And treatment of severe hypertension. Compared with nicardipine and nifedipine dihydropyridine calcium channel blockers, adipine is superior in selectivity, long-lasting and long-lasting, and has little effect on the heart.

Figure imgf000002_0001

阿折地平的结构式

Figure imgf000002_0001

A flat floor structure

At present, references to the preparation of agdipine include: European patents EP0266922; Chinese patent CN201010516967.7; Chinese Journal of Medicinal Chemistry, 2010, 20 (3): 192-194; Chinese Journal of Pharmaceutical Industry, 2008, 39 (3): 163-165; Chemical Industry and Engineering, 2009, 26 ( 1 ): 15-18; Qilu Pharmacy, 2005, 24 (6): 365-366. The preparation method of adipine in these literatures is based on the reaction of epichlorohydrin and diphenylamine with N-alkylation, cyclization, esterification, Pinner synthesis, neutralization, and oxime reaction. The intermediate 3-amino-3-iminopropionic acid-1-(diphenylfluorenyl)-3-azetidinyl acetate is prepared first, followed by 2-(3-nitrobenzylidene)acetyl Acepinedipine was obtained by the Hantzsch condensation of isopropyl acetate.

 The control of the solvent and reaction conditions in the esterification, Pinner synthesis and neutralization three-step reaction in this route is critical. Using the preparation methods provided by these documents, we found that the operation was cumbersome and the yield and purity were not satisfactory.

 In the esterification reaction, according to the method specifically reported in the above literature, the highest yield of the obtained product is only 85%, and the purity is poor, it is difficult to purify, and it is difficult to obtain a solid product.

Figure imgf000003_0001

副产物 (7 )和(8 )结构式 发明内容 We have found that 3-amino-3-iminopropionic acid-1- (3) is prepared by a three-step reaction from cyanoacetate-1-diphenylhydrazin-3-azetidinyl ester (3) according to the method specifically reported in the above literature. Diphenylhydrazino)-3-azetidinyl acetate (6), the reaction operation is cumbersome, and it is easy to produce by-products of hydrolysis of ester bonds and hydrolysis of imid bonds (7) and (8), three-step reaction. The total yield is only 20~30%, and the purification of the product is difficult, which seriously affects the quality of the final product and greatly increases the production cost.

Figure imgf000003_0001

Byproducts (7) and (8) structural formula Summary of the invention

It is an object of the present invention to provide a process for the preparation of the key intermediate of adipine, 3-amino-3-iminopropionic acid-1-(diphenylhydrazinyl)-3-azetidinyl acetate. The adipine intermediate of the present invention 3-amino-3-iminopropionic acid-1-(diphenylhydrazinyl)-3-azetidinyl acetate acetate has the following structural formula:

Figure imgf000004_0001
Figure imgf000004_0001

The preparation method of 3-amino-3-iminopropionic acid-1-(diphenylindenyl)-3-azetidinyl acetate of the present invention comprises the following steps: 1) Esterification: 1-diphenylhydrazin-3-azetidinol (2), cyanoacetic acid (1) and N,N-dicyclohexylcarbodiimide (DCC) in organic solvent at 0~ Reacting at 80 ° C, to obtain 7-diphenylindolyl-3-azetidinyl cyanoacetate (3);

 2) Pinner reaction: Add intermediate (3), absolute ethanol to dichlorosilane, stir and cool

To -20~25 °C, dry hydrogen chloride gas is passed, and then the reaction solution is kept sealed at -20~25 °C to obtain 3-imino-3-ethoxypropionic acid-1-(diphenylfluorenyl) -3-azetidinyl ester hydrochloride (4);

 3) Neutralization reaction: The intermediate (4) is dissolved in dichloromethane, and the base is added at -5 to 25 ° C to obtain 3-imino-3-ethoxypropionic acid-1-(diphenylhydrazine). Benzyl-3-azetidinyl ester (5);

 4) Formation reaction: The intermediate (5) is dissolved in acetonitrile, ammonium acetate is added, and the temperature is raised to 40 to 60 ° C to obtain 3-amino-3-iminopropionic acid-1-(diphenylfluorenyl)-3. – azetidinium acetate compound (6). detailed description

Example

 1. Preparation of cyanoacetic acid-1-diphenylhydrazine-3-azetidine (esterification)

Figure imgf000008_0001
Figure imgf000008_0001

 Method 1: Add 1-diphenylhydrazin-3-azetidinol (2, 235 g, 0.983 mol) and cyanoacetic acid (1, 100 g, 1.18 mol) to 1.5 mL of dichloromethane, and stir until fully dissolved. Ν, Ν-dicyclohexylcarbodiimide (DCC, 243 g, 1.18 mol) was added at 0-10 ° C and allowed to react at room temperature for 3 h. After the completion of the reaction, the reaction mixture was cooled to 0 to 5 ° C, and filtered, filtered, washed with a small portion of dichloromethane. The organic solvent was evaporated to dryness under reduced pressure and dried to give 275 g of white solid.

 Method 2: chloroform was used as the reaction solvent, and the operation was the same as above, and the reaction was carried out at 55 ° C for 5 hours, the HPLC purity was 98.7%, and the product yield was 95.3%.

 Method 3: Ethyl acetate was used as the reaction solvent, and the operation was the same as above, and the reaction was carried out at 55 ° C for 2 h, the HPLC purity was 98.9%, and the product yield was 96.1%.

Figure imgf000009_0001

Method 4: Using hydrazine as the reaction solvent, the operation was the same as above, and the reaction was carried out at 55 ° C for 7 h, the HPLC purity was 98.5%, and the product yield was 94.7%. 2. Preparation of 3-imino-3-ethoxypropionic acid-1-(diphenylfluorenyl)-3-azetidinyl ester hydrochloride (Pinner reaction)

Figure imgf000009_0001

 Intermediate 3 (270 g, 0.882 mol), absolute ethanol (61.8 mL, 1.06 mol) was added to 1.5 L of dry dichloromethane, cooled to -5 to 0 ° C in a water salt bath, and dried. HC1 gas for 2.5 h, after the completion of the aeration, the reaction solution was kept under stirring at 0 ° C for 6 h.

Allow to stand overnight at 0-4 °C. After completion of the reaction, the solvent was evaporated under reduced pressure to give an oily viscous intermediate 4 .

 3. Preparation of 3-imino-3-ethoxypropionic acid-1-(diphenylfluorenyl)-3-azetidinyl ester

Figure imgf000009_0002
Figure imgf000009_0002

 Method 1: Add 1.4 L of dichloromethane to Intermediate 4, cool to 0-5 ° C, add dry diethylamine (182 mL, 1.76 mol) to the solution, adjust pH 7-8, continue to stir after the dropwise addition. 2h. The mixture was suction filtered, and the filtrate was evaporated to dryness vacuo.

 Method 2: Diamine is used for neutralization, and the operation is the same as above.

 Method 3: Triethylamine is used for neutralization, and the operation is the same as above.

 Method 4: Ethylenediamine is used for neutralization, and the operation is the same as above.

Method 5: Add 1.4 L of dichloromethane to Intermediate 4, cool to 0-5 ° C, add potassium carbonate (242.88 g, 1.76 mol) to the solution in portions, adjust pH 7-8, continue stirring for 2 h. . The mixture was suction filtered, and the filtrate was evaporated to dryness vacuo. Method 6: Neutralize with sodium carbonate, and operate as above.

 Method 7: Neutralize with sodium hydroxide, and operate as above.

Figure imgf000010_0001

4. Preparation of 3-amino-3-iminopropionic acid-1-(diphenylindenyl)-3-azetidinyl acetate (formed into 脒)

Figure imgf000010_0001

 To the intermediate 5, 1.2 L of acetonitrile was added, and after dissolution, ammonium acetate (68.0 g, 0.882 mol) was added, and the mixture was heated to 55 ° C for 6 h. After the reaction, it was naturally cooled, crystallization, suction filtration, acetonitrile washing cake, and dried to give 236 g of a white solid. The total yield of the three-step reaction was 69.9 73.1%.

PAPER

https://pubs.rsc.org/en/content/articlelanding/2015/cc/c4cc09337b#!divAbstract

Abstract

A protocol for the coupling of 3-iodoazetidines with Grignard reagents in the presence of an iron catalyst has been developed. A variety of aryl, heteroaryl, vinyl and alkyl Grignards were shown to participate in the coupling process to give the products in good to excellent yields. Furthermore, a short formal synthesis towards a pharmacologically active molecule was shown.

Graphical abstract: Iron catalysed cross-couplings of azetidines – application to the formal synthesis of a pharmacologically active molecule

http://www.rsc.org/suppdata/cc/c4/c4cc09337b/c4cc09337b1.pdfPATENThttps://patents.google.com/patent/CN103509003A/zhAzelnidipine, whose chemical name is 3-(1-diphenylmethylazetidin-3-yl) 5-isopropyl 2-amino-1,4-dihydro-6-methyl 4-(3-nitrophenyl)-3,5-pyridinedicarboxylate, developed by Japan Sankyo Co., Ltd. and approved to be marketed in Japan in late May 2003. The existing synthesis method of azedipine is cumbersome, and the preparation of intermediate (VI) adopts column chromatography method, and the purification of product (I) also uses column chromatography method, which is not suitable for industrial production.

A method for preparing azeldipine, which is characterized in that it is prepared by the following steps.

[0006]

Figure CN103509003AD00041

Description of the drawings:

Figure 1 is a flow chart of the synthesis process of azeldipine.

[0025] Example 12-Preparation of (3-nitrobenzylidene) isopropyl acetoacetate (III)

[0026] Add 2.1kg of 3-nitrobenzaldehyde and 5L of isopropanol to the reaction kettle, start stirring, add 3kg of isopropyl acetoacetate, and stir. Add 43ml of anhydrous piperidine and 12ml of glacial acetic acid, and continue to stir until the solid is completely dissolved. Heat the temperature to 45°C and keep the reaction for 6h, then lower the temperature, stir and crystallize for 16h. Filter and collect the resulting filter cake. Put the obtained filter cake and 16L ethanol (industrial) into the reaction kettle, start stirring, beating, filtering, and collecting the filter cake. Put the filter cake in the baking tray, put it in the oven, and dry at 70-80°C. Collect the product 2-(3-nitrobenzylidene) isopropyl acetoacetate (III), about 2.7 kg.

[0027] Example 21-Preparation of benzhydryl-3-hydroxyazetidine (Intermediate V)

[0028] 9.6L of methanol, 5.4kg of benzhydrylamine (IV) and 3.33kg of epichlorohydrin were added to the reaction kettle, stirred at room temperature for 48 hours, the reaction was completed, the temperature was raised to 68°C, and the reaction was refluxed for 72h. Cool to room temperature. Concentrate under reduced pressure to remove methanol, and collect the filter cake by filtration. The filter cake was put into the reaction kettle, 19.2L of ether and 13.75L of 3mol/L NaOH solution were added, stirred, and the water layer was released after standing still. The ether layer was washed with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was collected. The ether was recovered under reduced pressure to dryness to obtain about 3.05 kg of 1-benzyl-3-hydroxyazetidine (Intermediate V).

[0029] Example 3 Preparation of cyanoacetic acid (1-diphenylmethylazetidin-3-yl) ester (Intermediate VI)

[0030] Put about 3.05g of intermediate (V), 27L of tetrahydrofuran and 1.7kg of cyanoacetic acid into the reactor, start stirring, turn on the chilled water of the reactor to cool down, and slowly add 3.1kgN, N’-dicyclohexyl to the reactor Diimine, control the temperature at IO0C -15°C, after the addition, close the chilled water in the reactor. Turn on the heating system, slowly increase the temperature to 55-60°C, and react for 10 hours. The material liquid was cooled to room temperature, filtered, and the filtrate was concentrated to dryness. Put 16.8L of ethyl acetate into the reaction kettle, stir to dissolve, then wash with water, dry with anhydrous sodium sulfate, filter, and collect the filtrate. Ethyl acetate was recovered under reduced pressure, petroleum ether was added to the solid residue, stirred, and filtered to obtain cyanoacetic acid (1-diphenylmethylazetidin-3-yl) ester (Intermediate VI), about 3.19 kg.

[0031] Example 4 Preparation of amidinoacetic acid (1-diphenylmethylazetidin-3-yl) ester acetate (VII)

[0032] Put 25L of dichloromethane, about 3.19kg of intermediate (VI), and 430g of ethanol into the reactor, start stirring, cool to below 0°C, and pass in hydrogen chloride gas until the temperature stabilizes below 0°C, at 0°C Let stand for 14 hours at °C. Concentrate under reduced pressure to remove most of the hydrogen chloride gas and recover the solvent dichloromethane. Add 25L of dichloromethane to the residue of the reaction kettle, stir, cool to below 0°C, and pass in ammonia until the temperature stabilizes below 0°C, and filter . The filtrate was poured into the reactor, concentrated under reduced pressure to recover the solvent to obtain a colorless liquid, added 22.8L of acetonitrile and 905g of amine acetate, heated to 55-60°C for 1.5 hours, stopped the reaction, filtered while hot, and recovered the filtrate under reduced pressure Solvent to dryness, add 3L of ether to the residue to crystallize, filter, and dry to obtain amidinoacetic acid (1-diphenylmethylazetidin-3-yl) ester acetate (Intermediate VII) about 3.2kg .

[0033] Example 5. Add about 3.2kg of Intermediate (VII), about 2.7kg of Intermediate (III), 21L of isopropanol and 585g of sodium methoxide to the reaction kettle, start stirring, heat to reflux and react for 4 hours, and cool to Below 10°C, filter, the filtrate is decompressed to recover the solvent to dryness, add 35L ethyl acetate to the residue to dissolve, wash with 6.5LX3 water, release the water layer, add anhydrous sodium sulfate to the ethyl acetate layer to dry, filter , Collect the filtrate, recover ethyl acetate under reduced pressure, add 4.2L of toluene to the residue,

3.4L of n-hexane was heated to dissolve, filtered, the filtrate was stirred to room temperature to crystallize, filtered and collected and dried, and the product was placed in an oven at 45-55°C to dry to obtain the crude azedipine (I), about 2.3kg.

[0034] Example 6, Refining

[0035] Put 8.8L ethyl acetate and 8.8L n-hexane into the reaction kettle, turn on the stirring, put about 2.3kg of the crude azeldipine into the reaction kettle, slowly heat up until the material is dissolved, add 180g of activated carbon and stir for 0.5h, while it is hot Filter, hydraulically filter the material to the crystallization dad, wash the filter cake with 5.5L ethyl acetate and 4.5L n-hexane solution, combine with the filtrate, cool to 0~5°C to crystallize, filter, collect the product, and place it in a hot air circulating oven After drying at 45-55°C, 2.2 g of azeldipine is obtained. The purity is 99.6% as measured by high performance liquid chromatography. The refined yield is 96.0%.

[0036] Example 7 Azedipin Refining

[0037] The mixed solvent was prepared according to the volume ratio of ethyl acetate and n-hexane of 2:1, 22L of the mixed solvent was put into the reactor, about 2.3kg of azedipine crude product was put into the reactor, and the temperature was slowly heated until the material was dissolved, Add 180g of activated carbon and stir for 0.5h, filter while hot, filter the material hydraulically into a crystallization kettle, wash the filter cake with a mixed solvent, combine the washing liquid with the filtrate, cool to 0~5°C for crystallization, filter, collect the product, and circulate the hot air Dry in an oven at a temperature of 45-55°C to obtain 2.2 g of azeldipine fine product, with a purity of 99.7% measured by high performance liquid chromatography.

[0038] Example 8 prepared a mixed solvent at a volume ratio of ethyl acetate and n-hexane of 1.5:1, put 22L of the mixed solvent into the reactor, put about 2.3kg of crude azeldipine into the reactor, and slowly heated to Dissolve the material, add 180g of activated carbon and stir for 0.5h, filter while it is hot, filter the material hydraulically into a crystallization kettle, wash the filter cake with a mixed solvent, combine the washing liquid and the filtrate, cool to 0~5°C to crystallize, filter, and collect the product. Dry in a hot air circulating oven at a temperature of 45-55°C to obtain

2.2g azeldipine is a fine product with a purity of 99.6% measured by high performance liquid chromatography.

PATENT

https://patents.google.com/patent/CN103183663B/zh

Azelnidipine (Azelnidipine) is a new type of dihydropyridine calcium channel blocker jointly developed by Sankyo Co., Ltd. and Ube Industries Co., Ltd., which inhibits the entry of calcium ions into excitable tissues and causes peripheral blood vessels And coronary artery vasodilation plays a role in lowering blood pressure. Clinically, it is widely used in patients with mild or moderate symptoms of primary hypertension, hypertension with renal dysfunction, and severe hypertension. Compared with similar antihypertensive drugs, azeldipine has a slow and long-lasting antihypertensive effect.

[0004] The chemical structure of azeldipine is similar to that of nifedipine:

Figure CN103183663BD00031

[0006] The Chinese patent CN87107150.9 reported the compound earlier and gave a detailed introduction to its synthesis; afterwards, most of the synthesis of azeldipine adopts this route:

Figure CN103183663BD00032

[0008] The reaction takes o-nitrobenzaldehyde and isopropyl acetoacetate as raw materials to prepare intermediate compound 5; takes benzhydrylamine and epichlorohydrin as raw materials to prepare compound 2, compound 2 and cyanoacetic acid act in DCC Compound 3 is prepared by the next reaction. Compound 3 is added with ethanol under the action of hydrogen chloride gas, ammonia gas ammonolysis, and acetate anion exchange to obtain compound 4. Compound 4 and compound 5 are under the action of sodium methoxide to obtain compound 1, namely azeldipine.

[0009] Wherein: Compound 3 can be purchased as an industrial product, or can be prepared according to the traditional method reported in the literature; Compound 5 is prepared according to the traditional method reported in the literature.

[0010] In the process of preparing amidine 4 in the traditional reaction route, hydrogen chloride gas and ammonia gas need to be passed in successively. Therefore, the reaction requires anhydrous reagents. According to literature reports, the reaction yield is about 70%. From the perspective of industrial synthesis, The application of anhydrous reagents will undoubtedly increase the cost, while the use of gas will increase the difficulty of operation and require the use of high-pressure equipment. At the same time, post-reaction processing is difficult and industrial production is difficult. Therefore, this step of the reaction requires further improvement.

With acetonitrile as a solvent, the crude product of reaction 2) was stirred until dissolved, ammonium acetate was added, and acetate anion exchange was performed to obtain the amidine compound 4;

Figure CN103183663BD00041

[0018] The second step: use toluene as a solvent, compound 4 and compound 5 in the use of sodium amide to obtain compound 1, namely azedipine

Figure CN103183663BD00042

[0020] The preferred technical solution of the present invention is characterized in that the temperature of reaction 1) is controlled below _5°C

Example 1: Preparation of azeldipine

[0030] Add 50 g of compound 3, 1500 mL of dichloromethane, and 16.64 mL of absolute ethanol to a 5L three-necked flask, and under mechanical stirring, pass HC1 gas below -5 °C to saturation, and after saturation, keep the reaction at -5 °C for 24 hours. Protect from light and nitrogen, slowly add the above reaction system to 1665ml of ammonia water with a concentration of 2.5-3.0% under the control of 0-5°C. After the addition, stir for 0.5h, stand for 0.5h, and separate the liquids. The dichloromethane layer was washed once with 2000 mL of saturated brine, left standing for 1.0 h, separated, and the dichloromethane layer was drained under reduced pressure to obtain a white solid. Without drying, it was directly added to 2000 mL of acetonitrile, and the temperature was slowly heated to dissolve. Add 11.7g of ammonium acetate, control the temperature at 55°C -60°C, and react for 2h under mechanical stirring. After cooling, the solid precipitated, filtered, and dried to obtain 57.55 g of amidine 4, the yield was 91.2%, the HPLC purity was 99.63%, and the melting point was 130-132.3°C.

[0031] 50g amidine 4, 43.5g compound 5, 1000mL toluene, and 7.7g sodium amide were added into a 1000mL three-necked flask, mechanically stirred, heated to reflux, and reacted for 4 hours. TLC detects that the reaction is complete and cools to room temperature to crystallize. Filter, put the solid directly into the mixed solution of toluene and n-hexane (1:1.2-1.5) without drying, heat up to reflux to clear, cool to 56°C naturally, add seed crystals, stop stirring, and cool to 25° C, filter. The solid was purified once more according to the above method, and dried under reduced pressure at 40°C for 48 hours to obtain 66.87g of α-crystal form of Azedipine, yield 88.2%, melting point: 121-123°C.

[0032] Example 2; Preparation of Azeldipine

[0033] Add 50g of compound 3, 1500mL of dichloromethane, 16·64mL of absolute ethanol into a 5L three-necked flask, and under mechanical stirring, pass HC1 gas below -5°C to saturation, and after saturation, -6°C to -8°C Incubate the reaction for 24h. Under the control of 0-5 °C, slowly add the above reaction system to ammonia water with a concentration of 2.5-3.0%, adjust the pH to 7.8-8.5, after adding, stir for 0.5h, stand for 0.5h, and separate. The dichloromethane layer was washed once with 2000 mL of saturated brine, left standing for 1.0 h, separated, and the dichloromethane layer was drained under reduced pressure to obtain a white solid. Without drying, it was directly added to 2000 mL of acetonitrile, and the temperature was slowly heated to dissolve. Add 11.7g of ammonium acetate, control the temperature at 55°C-60°C, and react for 2h under mechanical stirring. After cooling, the solid precipitated, filtered, and dried to obtain 59.0 lg of amidine 4 with a yield of 93.5%, an HPLC purity of 99.52%, and a melting point of 130.1-132.0°C.

[0034] 50g amidine 4, 43.5g compound 5, 1000mL toluene and 7.7g sodium amide were added to a 1000mL three-necked flask, mechanically stirred, heated to reflux, and reacted for 4 hours. TLC detects that the reaction is complete and cools to room temperature to crystallize. Filter, put the solid directly into the mixed solution of toluene and n-hexane (1:1.2-1.5) without drying, heat up to reflux to clear, cool to 56°C naturally, add seed crystals, stop stirring, and cool to 25° C, filter. The solid was refined once more according to the above method, and dried under reduced pressure at 40°C for 48 hours to obtain 68.31 g of α-crystal azedipine, yield 90.01%, melting point: 121 -123 °C.

[0035] Example 3: Preparation of Amidine 4

[0036] Add 50g of compound 3, 1500mL of dichloromethane, 16·64mL of absolute ethanol into a 5L three-necked flask, and under mechanical stirring, pass HC1 gas below -5°C to saturation, and after saturation, -7°C to -9°C Incubate the reaction for 24h. Under the control of 0-5 °C, slowly add the above reaction system to the ammonia water with a concentration of 2.5-3.0%, adjust the pH to 8.5-9.5, after adding, stir for 0.5h, stand for 0.5h, and separate. The dichloromethane layer was washed once with 2000 mL of saturated brine, left standing for 1.0 h, separated, and the dichloromethane layer was drained under reduced pressure to obtain a white solid. Without drying, it was directly added to 2000 mL of acetonitrile, and the temperature was slowly heated to dissolve. Add 11.7g of ammonium acetate, control the temperature at 55°C-60°C, and react for 2h under mechanical stirring. After cooling, the solid precipitated, filtered, and dried to obtain 59.5 g of amidine 4, HPLC purity 99.78%, melting point: 130.7-132·2°C.

Figure CN103183663BC00021

Step 2: Using toluene as a solvent, compound 4 and compound 5 under the action of sodium amide to obtain compound 1, namely azeldipine

Figure CN103183663BC00022

 PATENThttps://patents.google.com/patent/CN102453023A/zh

detailed description

[0007] In the synthesis workshop, benzhydrylamine is used as a raw material to be synthesized by addition, cyclization, esterification, acidification, ammoniation, condensation and other reactions. The crude azeodipine is refined, dried, mixed and packaged in a clean area. Fold the ground. The specific response is as follows:

[0008] 1. Addition and cyclization reaction

[0009] Methanol, benzhydrylamine, and epichlorohydrin were added to the reaction kettle, stirred at room temperature for 24hr, the reaction was completed, the reaction was heated to reflux for 24hr, cooled, filtered to collect the precipitated solid, and then the mother liquor was concentrated to recover the raw materials, and the heating was continued to reflux 18 After hours, collect the product, add dichloromethane and H2O to the obtained solid, adjust the pH to 10-11 with 40% NaOH while stirring in an ice bath, stand still, separate the organic layer, dry with anhydrous magnesium sulfate, and recover the dichloromethane under reduced pressure To dryness, a colorless solid compound III (1-benzyl-3-hydroxyazetidine) is obtained. After improvement, the raw materials are fully reacted, and the reaction yield of this step is improved. The mass yield is 75%. % Mentioned 85%.

[0010]

Figure CN102453023AD00041

[0011] 2. Esterification reaction

[0012] Add THF, compound (III), and cyanoacetic acid to the reaction kettle, stir evenly, add DCC in batches under ice bath stirring, control the temperature at 10°C~15°C, after the addition, remove the ice water bath, and slowly heat up React at 55°C~60°C for 18h. After the reaction is complete, cool, filter to remove insoluble materials, concentrate the filtrate to dryness, add ethyl acetate to the residue to dissolve, wash with water, dry with anhydrous magnesium sulfate, and recover ethyl acetate under reduced pressure. The residue was added with petroleum ether and stirred for crystallization, and the solid was collected by filtration to obtain compound IV (1-diphenylmethyl-3-azetidinyl cyanoacetate).

[0013]

Figure CN102453023AD00042

[0014] 3. Acidification and amination reaction

[0015] Dichloromethane, ethanol and intermediate (IV) were added to the reaction kettle respectively, mixed and stirred, cooled to about _5 ° C in an ice salt bath, and dried hydrogen chloride gas was introduced until saturation (about 1.5 hours) after . Let stand overnight at about -5°C, recover the solvent under reduced pressure at room temperature, add dichloromethane to the residue and stir, cool to about _5°C in an ice-salt bath, pass in the dried ammonia gas until saturation (about 3 hours) , Filtration to remove the insoluble matter, and the filtrate was decompressed to recover solvent at room temperature. Acetonitrile and ammonium acetate were added to the residue respectively, and the temperature was raised to 55~60°C for 2 hours with stirring. After the reaction was completed, it was cooled and filtered. 3-Azacyclobutanylamidinoacetate acetate), the reaction in this step is controlled at about _5°C, and the transesterification

The side reaction is reduced, and the reaction yield is improved.

[0016]

Figure CN102453023AD00043

[0017] 4. Condensation reaction

[0018] Add isopropanol, intermediate (III’), sodium methoxide and compound V to the reaction kettle, mix and stir, heat to reflux and react for 5 hours. After the reaction is complete, cool and filter, and the filtrate is decompressed to recover the solvent to dryness, leaving residue Add ethyl acetate to dissolve, wash with water, dry with anhydrous magnesium sulfate, recover ethyl acetate under reduced pressure to 1/4 of the total volume, add n-hexane, and stir at 50°C for 30 min. After cooling and crystallization, the solid was collected by filtration, and air-dried at 45°C to obtain the crude azedipine (I). After the crude product was dissolved in ethyl acetate-n-hexane mixed solvent, activated carbon was added for decolorization and impurity removal to achieve the purpose of purification.

Figure CN102453023AD00051

[0020] The refined product is dissolved in dioxane, refluxed with n-hexane, cooled and crystallized, and dried to obtain a solid that is boiled in cyclohexane, cooled and filtered, and dried to obtain α-crystalline form Azedipine.

Patent

Publication numberPriority datePublication dateAssigneeTitleCN102453023A *2010-10-212012-05-16大丰市天生药业有限公司Process for producing azelnidipineCN103130700A *2013-03-142013-06-05沈阳中海药业有限公司Preparation method of azelnidipine intermediateCN103509003A *2012-06-272014-01-15威海威太医药技术开发有限公司Preparation method of azelnidipine 
JP3491506B2 *1997-10-142004-01-26宇部興産株式会社Method for producing dihydropyridine derivativeCN101475521B *2008-11-132010-11-10青岛黄海制药有限责任公司Method for synthesizing acetate of 1-benzhydryl-3-azetidine amidino acetic ester 
TitleLIU, JIAN-FENG ET AL.: “Improved Synthesis of Azelnidipine”, CHINESE JOURNAL OF MEDICINAL CHEMISTRY, vol. 20, no. 3, 30 June 2010 (2010-06-30), pages 192 – 194 *ZHANG, KAI ET AL.: “Synthesis of Azelnidipine”, CHINESE JOURNAL OF PHARMACEUTICALS, vol. 39, no. 3, 31 March 2008 (2008-03-31), pages 163 – 165, XP025959789, DOI: doi:10.1016/j.ejphar.2008.12.041 * 
CN103130700B *2013-03-142015-04-29沈阳中海药业有限公司Preparation method of azelnidipine intermediateCN104860855B *2014-12-082017-06-16宁夏紫光天化蛋氨酸有限责任公司A kind of preparation method of the methylmercapto butyric acid ester of 2 hydroxyl of the D of high-purity, L 4CN105949102A *2016-06-202016-09-21许昌豪丰化学科技有限公司Production method of azelnidipine intermediatePublication numberPriority datePublication dateAssigneeTitleWO2014139410A1 *2013-03-142014-09-18Shenyang Zhonghai Pharmaceutical Co., Ltd.A kind of preparation method of azeldipine intermediateCN105461691A *2015-12-312016-04-06Weihai Disu Pharmaceutical Co., Ltd.A kind of preparation method of azeldipineCN106279109A *2016-08-182017-01-04Weihai Disu Pharmaceutical Co., Ltd.A kind of preparation method of azeldipineCN106543061A *2016-10-202017-03-29Weihai Disu Pharmaceutical Co., Ltd.Preparation method of N-diphenylmethylcyclobutane-3-alcohol 

References

  1. ^ Oizumi K, Nishino H, Koike H, Sada T, Miyamoto M, Kimura T (September 1989). “Antihypertensive effects of CS-905, a novel dihydropyridine Ca++ channel blocker”Jpn. J. Pharmacol51 (1): 57–64. doi:10.1254/jjp.51.57PMID 2810942.
Clinical data
Trade namesCalBlock,AZUSA,Azovas
AHFS/Drugs.comInternational Drug Names
Routes of
administration
Oral
ATC codenone
Legal status
Legal statusIn general: ℞ (Prescription only)
Identifiers
showIUPAC name
CAS Number123524-52-7 
PubChem CID65948
ChemSpider59352 
UNIIPV23P19YUG
KEGGD01145 
ChEMBLChEMBL1275868 
CompTox Dashboard (EPA)DTXSID3020120 
ECHA InfoCard100.162.151 
Chemical and physical data
FormulaC33H34N4O6
Molar mass582.657 g·mol−1
3D model (JSmol)Interactive image
hideSMILES[O-][N+](=O)c1cccc(c1)C5C(/C(=O)OC(C)C)=C(\NC(\N)=C5\C(=O)OC4CN(C(c2ccccc2)c3ccccc3)C4)C
hideInChIInChI=1S/C33H34N4O6/c1-20(2)42-32(38)27-21(3)35-31(34)29(28(27)24-15-10-16-25(17-24)37(40)41)33(39)43-26-18-36(19-26)30(22-11-6-4-7-12-22)23-13-8-5-9-14-23/h4-17,20,26,28,30,35H,18-19,34H2,1-3H3 Key:ZKFQEACEUNWPMT-UHFFFAOYSA-N 

/////////Azelnidipine, CS-905, RS-9054, INDIA 2020, APPROVALS 2020

#Azelnidipine, #CS-905, #RS-9054, #INDIA 2020, #APPROVALS 2020

CC1=C(C(C(=C(N1)N)C(=O)OC2CN(C2)C(C3=CC=CC=C3)C4=CC=CC=C4)C5=CC(=CC=C5)[N+](=O)[O-])C(=O)OC(C)C

EVEROLIMUS


Everolimus

Everolimus

159351-69-6[RN]
23,27-Epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclohentriacontine-1,5,11,28,29(4H,6H,31H)-pentone, 9,10,12,13,14,21,22,23,24,25,26,27,32,33,34,34a-hexadecahydro-9,27-dihydroxy-3-[(1R)-2-[(1S,3R,4R)-4-(2-hydr oxyethoxy)-3-methoxycyclohexyl]-1-methylethyl]-10,21-dimethoxy-6,8,12,14,20,26-hexamethyl-, (3S,6R,7E,9R,10R,12R,14S,15E,17E,19E,21S,26R,27R,34aS)-
23,27-epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclohentriacontine-1,5,11,28,29(4H,6H,31H)-pentone, 9,10,12,13,14,21,22,23,24,25,26,27,32,33,34,34a-hexadecahydro-9,27-dihydroxy-3-[(1R)-2-[(1S,3R,4R)-4-(2-hydroxyethoxy)-3-methoxycyclohexyl]-1-methylethyl]-10,21-dimethoxy-6,8,12,14,20,26-hexamethyl-, (3S,6R,7E,9R,10R,12R,14S,15E,17E,19E,21S,23S,26R,27R,34aS)-
42-O-(2-Hydroxyethyl)rapamycin

  • Synonyms:RAD-001, SDZ-RAD, Afinitor
  • ATC:L04AA18

Use:immunosuppressantChemical name:42-O-(2-hydroxyethyl)rapamycinFormula:C53H83NO14

  • MW:958.24 g/mol
  • CAS-RN:159351-69-6

EverolimusCAS Registry Number: 159351-69-6CAS Name: 42-O-(2-Hydroxyethyl)rapamycinAdditional Names: 40-O-(2-hydroxyethyl)rapamycinManufacturers’ Codes: RAD-001; SDZ RADTrademarks: Certican (Novartis)Molecular Formula: C53H83NO14Molecular Weight: 958.22Percent Composition: C 66.43%, H 8.73%, N 1.46%, O 23.38%Literature References: Macrolide immunosuppressant; derivative of rapamycin, q.v. Inhibits cytokine-mediated lymphocyte proliferation. Prepn: S. Cottens, R. Sedrani, WO9409010eidem, US5665772 (1994, 1997 both to Sandoz). Pharmacology: W. Schuler et al., Transplantation64, 36 (1997). Whole blood determn by LC/MS: N. Brignol et al., Rapid Commun. Mass Spectrom.15, 898 (2001); by HPLC: S. Baldelli et al.J. Chromatogr. B816, 99 (2005). Clinical pharmacokinetics in combination with cyclosporine: J. M. Kovarik et al., Clin. Pharmacol. Ther.69, 48 (2001). Clinical study in prevention of cardiac-allograft vasculopathy: H. J. Eisen et al.,N. Engl. J. Med.349, 847 (2003). Review: F. J. Dumont et al., Curr. Opin. Invest. Drugs2, 1220-1234 (2001); B. Nashan, Ther. Drug Monit.24, 53-58 (2002).Therap-Cat: Immunosuppressant.Keywords: Immunosuppressant.эверолимус[Russian][INN]إيفيروليموس[Arabic][INN]依维莫司[Chinese][INN]Trade Name:Certican® / Zortress® / Afinitor®MOA:mTOR inhibitorIndication:Rejection of organ transplantation; Renal cell carcinoma; Advanced renal cell carcinoma (RCC); Advanced breast cancer; Pancreatic cancer; Renal angiomyolipoma; Tuberous sclerosis complex (TSC); Rejection in heart transplantation; Rejection of suppression renal transplantation; Subependymal giant cell astrocytoma; neuroendocrine tumors (NET); Advanced gastrointestinal tumorsStatus:ApprovedCompany:Novartis (Originator)Sales:$1,942 Million (Y2015);
$1,902 Million (Y2014);
$1,558 Million (Y2013);
$1,007 Million (Y2012);
$630 Million (Y2011);ATC Code:L04AA18Approved Countries or Area

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2012-08-29New dosage formAfinitor DisperzRenal cell carcinoma , Advanced breast cancer, Pancreatic cancer, Renal angiomyolipoma, Tuberous sclerosis complex (TSC)Tablet, For suspension2 mg/3 mg/5 mgNovartisPriority
2010-04-20New strengthZortressAdvanced renal cell carcinoma (RCC)Tablet0.25 mg/0.5 mg/0.75 mgNovartis 
2009-03-30Marketing approvalAfinitorAdvanced renal cell carcinoma (RCC)Tablet2.5 mg/5 mg/7.5 mg/10 mgNovartisPriority
Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2016-06-02New indicationAfinitorneuroendocrine tumors (NET), Advanced gastrointestinal tumorsTablet Novartis 
2011-09-02Marketing approvalVotubiaAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet2.5 mg/5 mg/10 mgNovartisOrphan; Conditional Approval
2011-09-02Marketing approvalVotubiaAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet, Orally disintegrating2 mg/3 mg/5 mgNovartisOrphan; Conditional Approval
2009-08-03Marketing approvalAfinitorAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet2.5 mg/5 mg/10 mgNovartis 
Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2011-12-22New indicationCerticanRejection of suppression renal transplantationTablet0.25 mg/0.5 mg/0.75 mgNovartis 
2007-01-26Marketing approvalCerticanRejection in heart transplantationTablet0.25 mg/0.5 mg/0.75 mgNovartis 

More

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2014-02-13Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet2.5 mgNovartis 
2013-01-22Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet10 mgNovartis 
2013-01-22Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet5 mgNovartis 

More

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2003-07-18Marketing approvalCerticanRejection of organ transplantation, Renal cell carcinomaTablet0.25 mg/0.5 mg/0.75 mgNovartis 

clip

Active Substance The active substance Everolimus is a hydroxyethyl derivative of rapamycin, which is a macrolide, isolated from the micro-organism Streptomyces hygroscopicus. The guideline, impurities in new active substances ICHQ 3A (R), does not apply to active substance of fermented origin. Everolimus (INN) or 42-O-(2-hydroxyethyl)-rapamycin (chemical name) or C5 3H8 3N O1 4 has been fully described. The molecule is amorphous and is stabilised with an antioxidant. Its physico-chemical properties including parameters such as solubility, pH, specific rotation, potential polymorphism and potential isomerism have been fully characterised. Everolimus is a white to faintly yellow amorphous powder. It is almost insoluble in water, is unstable at temperatures above 25 °C and is sensitive to light. In addition, possible isomerism has been investigated. Everolimus contains 15 asymmetric carbon atoms and 4 substituted double bonds. The configuration of the asymmetric carbon atoms and the double bonds is guaranteed by the microbial origin of Rapamycin. The configuration is not affected by the chemical synthesis. Polymorphism has been comprehensively discussed and it was demonstrated that the molecule domain remains amorphous.

str1

Synthesis of Everolimus The manufacturing process consists of four main steps, (1) fermentation, (2) extraction of rapamycin from the fermentation broth, (3) chemical modification of rapamycin starting material, (4) purification of crude everolimus and stabilisation with BHT. The choice of the stabilizer has been sufficiently explained and justified by experimental results. Interactions products of Everolimus and the antioxidant were not detected, or were below detection limit. Rapamycin, obtained by a fermentation process, was used as the starting material. Reaction conditions and the necessary in-process controls are described in detail. Adequate specifications for starting materials and isolated intermediates and descriptions of the test procedures have been submitted. Control of the quality of solvents, reagents and auxiliary materials used in the synthesis has been adequately documented. It is stated by the manufacturer of rapamycin solution that no starting material of animal or human origin is used in the fermentation. Elucidation of structure and other characteristics The structure of Everolimus has been fully elucidated using several spectroscopic techniques such as ultraviolet absorption spectroscopy (UV), Infra-red spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance spectroscopy (1 H and 13C NMR), mass spectroscopy, diffractometry (X-ray) and elemental analysis. Related substances An extensive discussion was presented on the related substances. The complex structure of Everolimus allows several possible degradation pathways to occur at various positions of the molecule. Everolimus alone is extremely sensitive to oxidation. By the addition of an antioxidant, the sensitivity to oxidation is significantly reduced (the antioxidant is known to react as a scavenger of peroxide radicals). It is assumed that oxidation of Everolimus proceeds via a radical mechanism. All the requirements set in the current testing instruction valid for Everolimus are justified on the basis of the results obtained during development and manufactured at the production scale.

fda

Everolimus was first approved by Swiss Agency for therapeutic products,Swissmedic on July 18, 2003, then approved by Pharmaceuticals and Medicals Devices Agency of Japan (PMDA) on April 23, 2004, and approved by the U.S. Food and Drug Administration (FDA) on Mar 30, 2009, approved by European Medicine Agency (EMA) on Aug 3, 2009. It was developed and marketed as Certican® by Novartis in SE.

Everolimus is an inhibitor of mammalian target of rapamycin (mTOR). It is indicated for the treatment of renal cell cancer and other tumours and currently used as an immunosuppressant to prevent rejection of organ transplants.

Certican® is available as tablet for oral use, containing 0.25, 0.5 or 0.75 mg of free Everolimus. The recommended dose is 10 mg once daily with or without food for advanced HR+ breast cancer, advanced progressive neuroendocrine tumors, advanced renal cell carcinoma or renal angiomyolipoma with tuberous sclerosis complex.
Everolimus, also known as RAD001, is a derivative of the natural macrocyclic lactone sirolimus with immunosuppressant and anti-angiogenic properties. In cells, everolimus binds to the immunophilin FK Binding Protein-12 (FKBP-12) to generate an immunosuppressive complex that binds to and inhibits the activation of the mammalian Target of Rapamycin (mTOR), a key regulatory kinase. Inhibition of mTOR activation results in the inhibition of T lymphocyte activation and proliferation associated with antigen and cytokine (IL-2, IL-4, and IL-15) stimulation and the inhibition of antibody production.

Everolimus is a medication used as an immunosuppressant to prevent rejection of organ transplants and in the treatment of renal cell cancer and other tumours. Much research has also been conducted on everolimus and other mTOR inhibitors as targeted therapy for use in a number of cancers.[medical citation needed]

It is the 40-O-(2-hydroxyethyl) derivative of sirolimus and works similarly to sirolimus as an inhibitor of mammalian target of rapamycin (mTOR).

It is marketed by Novartis under the trade names Zortress (USA) and Certican (European Union and other countries) in transplantation medicine, and as Afinitor (general tumours) and Votubia (tumours as a result of TSC) in oncology. Everolimus is also available from Biocon, with the brand name Evertor.

Medical uses

Everolimus is approved for various conditions:

  • Advanced kidney cancer (US FDA approved in March 2009)[3]
  • Prevention of organ rejection after renal transplant(US FDA April 2010)[4]
  • Subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis (TS) in patients who are not suitable for surgical intervention (US FDA October 2010)[5]
  • Progressive or metastatic pancreatic neuroendocrine tumors not surgically removable (May 2011)[6]
  • Breast cancer in post-menopausal women with advanced hormone-receptor positive, HER2-negative type cancer, in conjunction with exemestane (US FDA July 2012)[7]
  • Prevention of organ rejection after liver transplant(Feb 2013)
  • Progressive, well-differentiated non-functional, neuroendocrine tumors (NET) of gastrointestinal (GI) or lung origin with unresectable, locally advanced or metastatic disease (US FDA February 2016).[8]
  • Tuberous sclerosis complex-associated partial-onset seizures for adult and pediatric patients aged 2 years and older. (US FDA April 2018).[9]

UK National Health Service

NHS England has been criticised for delays in deciding on a policy for the prescription of everolimus in the treatment of Tuberous Sclerosis. 20 doctors addressed a letter to the board in support of the charity Tuberous Scelerosis Association saying ” around 32 patients with critical need, whose doctors believe everolimus treatment is their best or only option, have no hope of access to funding. Most have been waiting many months. Approximately half of these patients are at imminent risk of a catastrophic event (renal bleed or kidney failure) with a high risk of preventable death.”[10] In May 2015 it was reported that Luke Henry and Stephanie Rudwick, the parents of a child suffering from Tuberous Sclerosis were trying to sell their home in Brighton to raise £30,000 to pay for treatment for their daughter Bethany who has tumours on her brain, kidneys and liver and suffers from up to 50 epileptic fits a day.[11]

Clinical trials

As of October 2010, Phase III trials are under way in gastric cancerhepatocellular carcinoma, and lymphoma.[12] The experimental use of everolimus in refractory chronic graft-versus-host disease was reported in 2012.[13]

Interim phase III trial results in 2011 showed that adding Afinitor (everolimus) to exemestane therapy against advanced breast cancer can significantly improve progression-free survival compared with exemestane therapy alone.[14]

A study published in 2012, shows that everolimus sensitivity varies between patients depending on their tumor genomes.[15] A group of patients with advanced metastasic bladder carcinoma (NCT00805129) [16] treated with everolimus revealed a single patient who had a complete response to everolimus treatment for 26 months. The researchers sequenced the genome of this patient and compared it to different reference genomes and to other patients’ genomes. They found that mutations in TSC1 led to a lengthened duration of response to everolimus and to an increase in the time to cancer recurrence. The mutated TSC1 apparently had made these tumors vulnerable to treatment with everolimus.[medical citation needed]

phase 2a randomized, placebo-controlled everolimus clinical trial published in 2014 showed that everolimus improved the response to an influenza vaccine by 20% in healthy elderly volunteers.[17] A phase 2a randomized, placebo-controlled clinical trial published in 2018 showed that everolimus in combination with dactolisib decreased the rate of reported infections in an elderly population.[17]

Mechanism

Compared with the parent compound rapamycin, everolimus is more selective for the mTORC1 protein complex, with little impact on the mTORC2 complex.[18] This can lead to a hyper-activation of the kinase AKT via inhibition on the mTORC1 negative feedback loop, while not inhibiting the mTORC2 positive feedback to AKT. This AKT elevation can lead to longer survival in some cell types.[medical citation needed] Thus, everolimus has important effects on cell growth, cell proliferation and cell survival.

mTORC1 inhibition by everolimus has been shown to normalize tumor blood vessels, to increase tumor-infiltrating lymphocytes, and to improve adoptive cell transfer therapy.[19]

Additionally, mTORC2 is believed to play an important role in glucose metabolism and the immune system, suggesting that selective inhibition of mTORC1 by drugs such as everolimus could achieve many of the benefits of rapamycin without the associated glucose intolerance and immunosuppression.[18]

TSC1 and TSC2, the genes involved in tuberous sclerosis, act as tumor suppressor genes by regulating mTORC1 activity. Thus, either the loss or inactivation of one of these genes lead to the activation of mTORC1.[20]

Everolimus binds to its protein receptor FKBP12, which directly interacts with mTORC1, inhibiting its downstream signaling. As a consequence, mRNAs that code for proteins implicated in the cell cycle and in the glycolysis process are impaired or altered, and tumor growth is inhibited.[20]

Adverse reactions

A trial using 10 mg/day in patients with NETs of GI or lung origin reported “Everolimus was discontinued for adverse reactions in 29% of patients and dose reduction or delay was required in 70% of everolimus-treated patients. Serious adverse reactions occurred in 42% of everolimus-treated patients and included 3 fatal events (cardiac failure, respiratory failure, and septic shock). The most common adverse reactions (incidence greater than or equal to 30%) were stomatitis, infections, diarrhea, peripheral edema, fatigue and rash. The most common blood abnormalities found (incidence greater than or equal to 50%) were anemia, hypercholesterolemia, lymphopenia, elevated aspartate transaminase (AST) and fasting hyperglycemia.”.[8]

Role in heart transplantation

Everolimus may have a role in heart transplantation, as it has been shown to reduce chronic allograft vasculopathy in such transplants. It also may have a similar role to sirolimus in kidney and other transplants.[21]

Role in liver transplantation

Although, sirolimus had generated fears over use of m-TOR inhibitors in liver transplantation recipients, due to possible early hepatic artery thrombosis and graft loss, use of everolimus in the setting of liver transplantation is promising. Jeng et al.,[22] in their study of 43 patients, concluded the safety of everolimus in the early phase after living donor liver transplantation. In their study, no hepatic artery thrombosis or wound infection was noted. Also, a possible role of everolimus in reducing the recurrence of hepatocellular carcinoma after liver transplantation was correlated. A target trough level of 3 ng/mL at 3 months was shown to be beneficial in recipients with pre-transplant renal dysfunction. In their study, 6 of 9 renal failure patients showed significant recovery of renal function, whereas 3 showed further deterioration, one of whom required hemodialysis.[23] Recently published report by Thorat et al. showed a positive impact on hepatocellular carcinoma (HCC) when everolimus was used as primary immunosuppression starting as early as first week after living donor liver transplantation (LDLT) surgery.[24] In their retrospective and prospective analysis at China Medical University Hospital in Taiwan, the study cohort (n=66) was divided in two groups depending upon the postoperative immunosuppression. Group A: HCC patients that received Everolimus + Tacrolimus based immunosuppressive regimen (n=37). Group B: HCC patients that received standard Tacrolimus based immunosuppressive regimen without everolimus (n=29). The target trough level for EVR was 3 to 5 ng/ml while for TAC it was 8–10 ng/ml. The 1-year, 3-year and 4-year overall survival achieved for Group A patients (Everolimus group) was 94.95%, 86.48% and 86.48%, respectively while for Group B patients it was 82.75%, 68.96%, and 62.06%, respectively (p=0.0217). The first 12-month report of ongoing Everolimus multicenter prospective trial in LDLT (H2307 trial), Jeng LB et al. have shown a 0% recurrence of HCC in everolimus group at 12 months.[25] Jeng LB concluded that an early introduction of everolimus + reduced tacrolimus was non-inferior to standard tacrolimus in terms of efficacy and renal function at 12 months, with HCC recurrence only in tacrolimus control patients.

Use in vascular stents

Everolimus is used in drug-eluting coronary stents as an immunosuppressant to prevent restenosis. Abbott Vascular produce an everolimus-eluting stent (EES) called Xience Alpine. It utilizes the Multi-Link Vision cobalt chromium stent platform and Novartis’ everolimus. The product is widely available globally including the US, the European Union, and Asia-Pacific (APAC) countries. Boston Scientific also market EESes, recent offerings being Promus Elite and Synergy.[citation needed]

Use in aging

Inhibition of mTOR, the molecular target of everolimus, extends the lifespan of model organisms including mice,[26] and mTOR inhibition has been suggested as an anti-aging therapy. Everolimus was used in a clinical trial by Novartis, and short-term treatment was shown to enhance the response to the influenza vaccine in the elderly, possible by reversing immunosenescence.[27] Everolimus treatment of mice results in reduced metabolic side effects compared to sirolimus.[18]Route 1

Reference:1. US5665772A.

2. Drug. Future 199924, 22-29.Route 2

Reference:1. WO2014203185A1.Route 3

Reference:1. WO2012103959A1.Route 4

Reference:1. CN102731527A.

SYN

Synthetic Reference

Wang, Feng. Everolimus intermediate and preparation method thereof. Assignee Shanghai Institute of Pharmaceutical Industry, Peop. Rep. China; China State Institute of Pharmaceutical Industry. CN 109776570. (2019).

SYN 2

Synthetic Reference

Polymer compositions containing a macrocyclic triene compound; Shulze, John E.; Betts, Ronald E.; Savage, Douglas R.; Assignee Sun Bow Co., Ltd., Bermuda; Sun Biomedical Ltd. 2003; Patent Information; Nov 06, 2003; WO 2003090684 A2

SYN 3

Synthetic Reference

Wang, Feng. Everolimus intermediate and preparation method thereof. Assignee Shanghai Institute of Pharmaceutical Industry, Peop. Rep. China; China State Institute of Pharmaceutical Industry. CN 109776570. (2019).

SYN 4

Synthetic Reference

Zabudkin, Oleksandr; Schickaneder, Christian; Matviienko, Iaroslav; Sypchenko, Volodymyr. Method for the synthesis of rapamycin derivatives. Assignee Synbias Pharma AG, Switz. EP 3109250. (2016).

SYN 5

str1

Synthetic Reference

Lu, Shiyong; Zhang, Xiaotian; Chen, Haohan; Ye, Weidong. Preparation of sirolimus 40-ether derivative. Assignee Zhejiang Medicine Co., Ltd. Xinchang Pharmaceutical Factory, Peop. Rep. China. CN 105237549. (2016).

SYN 6

Synthetic Reference

Seo, Jeong U.; Ham, Yun Beom; Kang, Heung Mo; Lee, Gwang Mu; Kim, In Gyu; Kim, Jeong Jin; Park, Ji Su. Preparation of everolimus and synthetic intermediate thereof. Assignee CKD Bio Corp., S. Korea. KR 1529963 (2015).

SYN

EP 0663916; EP 0867438; JP 1996502266; JP 1999240884; US 5665772; WO 9409010

Alkylation of rapamycin (I) with 2-(tert-butyldimethylsilyloxy)ethyl triflate (II) by means of 2,6-lutidine in hot toluene gives the silylated target compound (III), which is deprotected by means of 1N HCl in methanol.

SYN

J Label Compd Radiopharm 1999,42(1),29

The compound has been obtained biosynthetically by an optimized fermentation process using Streptomyces hygroscopicus mutant RSH 1701 with a complex culture medium were [14C]-labeled (1R,3R,4R)-2,3-dichydroxycyclo-hexanecarboxylic acid (I) and [14C]-labeled (S)-pipecolic acid (II) have been added. This fermentation process yielded [14C]-labeled rapamycin (III), which was finally selectively O-alkylated at the C-40 position with monosilylated ethylene glycol triflate in DMSO/dimethoxyethane.

SYN

The reaction of the labeled acylated (+)-bornane-10,2-sultam (IV) with triethyl phosphite gives the phosphonate (V), which is treated with paraformaldehyde, galvinoxyl and K2CO3 yielding the acrylate derivative (VI). The cyclization of (VI) with butadiene (VII) by means of diethylaluminum chloride and galvinoxyl (as radical scavenger) affords the cyclohexene-carboxamide derivative (VIII), which is hydrolyzed with LiOH in THF/water giving the (1R)-3-cyclohexenecarboxylic acid (IX). The oxidation of (IX) with m-chloroperbenzoic acid and triethylamine in CCl4 yielded regioselectively the hydroxylactone (X), which is finally hydrolyzed with HCl to the labeled intermediate (I).

SYN

The reaction of the labeled acylated (-)-bornane-10,2-sultam (XI) with benzophenone imine (XII) gives the glycylsultam derivative (XIII), which is alkylated with 4-iodobutyl chloride (XIV) by means of butyllithium and DMPU in THF yielding intermediate (XV). The selective hydrolysis of (XV) with HCl affords the omega-chloro-L-norleucine derivative (XVI), which is cyclized by means of tetrabutylammonium fluoride and DIEA in hot acetonitrile giving the (2S)-piperidyl derivative (XVII). Finally, this compound is hydrolyzed with LiOH in THF/water to the labeled intermediate (II).

clipRapamycin is a known macrolide antibiotic produced by Streptomvces hvgroscopicus. having the structure depicted in Formula A:

Figure imgf000003_0001

See, e.g., McAlpine, J.B., et al., J. Antibiotics (1991) 44: 688; Schreiber, S.L., et al., J. Am. Chem. Soc. (1991) J_13: 7433‘- US Patent No. 3 929 992. Rapamycin is an extremely potent immunosuppressant and has also been shown to have antitumor and antifungal activity. Its utility as a pharmaceutical, however, is restricted by its very low and variable bioavailabiiity as well as its high toxicity. Moreover, rapamycin is highly insoluble, making it difficult to formulate stable galenic compositions.

Everolimus, 40-O-(2-hydroxyethyl)-rapamycin of formula (1) is a synthetic derivative of rapamycin (sirolimus) of formula (2), which is produced by a certain bacteria strain and is also pharmaceutically active.

Figure imgf000002_0002

(1)                                                                                                               (2)

Everolimus is marketed under the brand name Certican for the prevention of rejection episodes following heart and kidney transplantation, and under the brand name Afinitor for treatment of advanced kidney cancer.

Due to its complicated macrolide chemical structure, everolimus is, similarly as the parent rapamycin, an extremely unstable compound. It is sensitive, in particular, towards oxidation, including aerial oxidation. It is also unstable at temperatures higher than 25°C and at alkaline pH.

Everolimus and a process of making it have been disclosed in WO 94/09010

Synthesis

Alkylation of rapamycin (I) with 2-(tert-butyldimethylsilyloxy)ethyl triflate (II) by means of 2,6-lutidine in hot toluene gives the silylated target compound (III), which is deprotected by means of 1N HCl in methanol (1). (Scheme 21042401a) Manufacturer Novartis AG (CH). References 1. Cottens, S., Sedrani, R. (Sandoz-Refindungen VmbH; Sandoz-Patent GmbH; Sandoz Ltd.). O-Alkylated rapamycin derivatives and their use, particularly as immunosuppressants. EP 663916, EP 867438, JP 96502266, US 5665772, WO 9409010.EP 0663916; EP 0867438; JP 1996502266; JP 1999240884; US 5665772; WO 9409010

…………..

SYNTHESIS

https://www.google.com/patents/WO2012103960A1

(US 5,665,772, EP 663916). The process principle is shown in the scheme below, wherein the abbreviation RAP-OH has been used as an abbreviation for the rapamycin structure of formula (2) above, L is a leaving group and P is a trisubstituted silyl group serving as a OH- protective group.

RAP-OH + L-CH2-CH2-0-P — –> RAP-O-CH2-CH2-O-P — – > RAP-O-CH2-CH2-OH

(2)                                                 (4)                                                                 (1)

Specifically, the L- group is a trifluoromethanesulfonate (triflate) group and the protective group P- is typically a tert-butyldimethylsilyloxy- group. Accordingly, the known useful reagent within the above general formula (3) for making everolimus from rapamycin is 2-(tert-butyldimethylsilyloxy)ethyl triflate of formula (3 A):

Figure imgf000003_0001

According to a known synthetic procedure disclosed in Example 8 of WO 94/09010 and in Example 1 of US application 2003/0125800, rapamycin (2) reacts in hot toluene and in the presence of 2,6-lutidine with a molar excess of the compound (3 A), which is charged in several portions, to form the t-butyldimethylsilyl-protected everolimus (4A). This compound is isolated and deprotected by means of IN aqueous HC1 in methanol. Crude everolimus is then purified by column chromatography. Yields were not reported.

Figure imgf000004_0001

(2)                                       (3A)                              (4A)                                (1)

In an article of Moenius et al. (J. Labelled Cpd. Radiopharm. 43, 113-120 (2000)), which used the above process for making C14-labelled and tritiated everolimus, a diphenyl- tert.butylsilyloxy -protective group was used as the alkylation agent of formula (3B).

Figure imgf000004_0002

Only 8% yield of the corresponding compound (4B)

Figure imgf000004_0003

and 21% yield of the compound (1) have been reported.

Little is known about the compounds of the general formula (3) and methods of their preparation. The synthesis of the compound (3 A) was disclosed in Example 1 of US application 2003/0125800. It should be noted that specification of the reaction solvent in the key step B of this synthesis was omitted in the disclosure; however, the data about isolation of the product allow for estimation that such solvent is dichloromethane. Similarly also a second article of Moenius et al. (J. Labelled Cpd. Radiopharm.42, 29-41 (1999)) teaches that dichloromethane is the solvent in the reaction.

It appears that the compounds of formula (3) are very reactive, and thus also very unstable compounds. This is reflected by the fact that the yields of the reaction with rapamycine are very low and the compound (3) is charged in high molar extent. Methods how to monitor the reactivity and/or improve the stability of compounds of general formula (3), however, do not exist.

Thus, it would be useful to improve both processes of making compounds of formula (3) and, as well, processes of their application in chemical synthesis.

xample 6: 40-O-[2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl]rapamycin

In a 100 mL flask, Rapamycin (6 g, 6.56 mmol) was dissolved in dimethoxyethane (4.2 ml) and toluene (24 ml) to give a white suspension and the temperature was raised to 70°C. After 20 min, N,N-diisopropylethylamine (4.56 ml, 27.6 mmol) and 2-((2,3-dimethylbutan-2- yl)dimethylsilyloxy)ethyl trifluoromethanesulfonate (8.83 g, 26.3 mmol) were added in 2 portions with a 2 hr interval at 70°C. The mixture was stirred overnight at room temperature, then diluted with EtOAc (40 ml) and washed with sat. NaHC03 (30 ml) and brine (30 ml). The organic layer was dried with Na2S04, filtered and concentrated. The cmde product was chromatographed on a silica gel column (EtOAc/heptane 1/1 ; yield 4.47 g).

Example 7: 40-O-(2-hydroxyethyl)-rapamycin [everolimus]

In a 100 mL flask, 40-O-[2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl]rapamycin (4.47 g, 4.06 mmol) was dissolved in methanol (20 ml) to give a colorless solution. At 0°C, IN aqueous hydrochloric acid (2.0 ml, 2.0 mmol) was added and the mixture was stirred for 90 min. The reaction was followed by TLC (ethyl acetate/n-heptane 3 :2) and HPLC. Then 20 ml of saturated aqueous NaHC03 were added, followed by 20 ml of brine and 80 ml of ethyl acetate. The phases were separated and the organic layer was washed with saturated aqueous NaCl until pH 6/7. The organic layer was dried by Na2S04, filtered and concentrated to yield 3.3 g of the product.

……………………….

SYNTHESIS

https://www.google.co.in/patents/WO1994009010A1

Example 8: 40-O-(2-Hydroxy)ethyl-rapamycin

a) 40-O-[2-(t-Butyldimethylsilyl)oxy]ethyl-rapamycin

A solution of 9.14 g (10 mmol) of rapamycin and 4.70 mL (40 mmol) of 2,6-lutidine in 30 mL of toluene is warmed to 60°C and a solution of 6.17 g (20 mmol) of 2-(t-butyldimethylsilyl)oxyethyl triflate and 2.35 mL (20 mmol) of 2,6-lutidine in 20 mL of toluene is added. This mixture is stirred for 1.5h. Then two batches of a solution of 3.08 g (10 mmol) of triflate and 1.2 mL (10 mmol) of 2,6-lutidine in 10 mL of toluene are added in a 1.5h interval. After addition of the last batch, stirring is continued at 60°C for 2h and the resulting brown suspension is filtered. The filtrate is diluted with ethyl acetate and washed with aq. sodium bicarbonate and brine. The organic solution is dried over anhydrous sodium sulfate, filtered and concentrated. The residue is purified by column chromatography on silica gel (40:60 hexane-ethyl acetate) to afford 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl-rapamycin as a white solid: 1H NMR (CDCl3) δ 0.06 (6H, s), 0.72 (1H, dd), 0.90 (9H, s), 1.65 (3H, s), 1.75 (3H, s), 3.02 (1H, m), 3.63 (3H, m), 3.72 (3H, m); MS (FAB) m/z 1094 ([M+Na]+), 1022 ([M-(OCH3+H2O)]+).

b) 40-O-(2-Hydroxy)ethyl-rapamycin

To a stirred, cooled (0°C) solution of 4.5 g (4.2 mmol) of 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl-rapamycin in 20 mL of methanol is added 2 mL of IN HCl. This solution is stirred for 2h and neutralized with aq. sodium bicarbonate. The mixture is extracted with three portions of ethyl acetate. The organic solution is washed with aq.

sodium bicarbonate and brine, dried over anhydrous sodium sulfate, filtered and

concentrated. Purification by column chromatography on silica gel (ethyl acetate) gave the title compound as a white solid:1H NMR (CDCl3) δ 0.72 (1H, dd), 1.65 (3H, s), 1.75 (3H, s), 3.13 (5H, s and m), 3.52-3.91 (8H, m); MS (FAB) m/z 980 ([M+Na]+), 926 ([M-OCH3]+), 908 ([M-(OCH3+H2O)]+), 890 ([M-(OCH3+2H2O)]+), 876 ([M-(2CH3OH+OH)]+), 858 ([M-(OCH3+CH3OH+2H2O)]+).

MBA (rel. IC50) 2.2

IL-6 dep. prol. (rel. IC50) 2.8

MLR (rel. IC50) 3.4

…………………..

synthesis

Everolimus (Everolimus) was synthesized by the Sirolimus (sirolimus, also known as rapamycin Rapamycin) ether from. Sirolimus is from the soil bacterium Streptomyces hygroscopicus isolated metabolites. Activation end sirolimus (triflate, Tf) the other end of the protection (t-butyldimethylsilyl, TBS) of ethylene glycol 1 reaction of 2 , because the hydroxyl group 42 hydroxyl site over the 31-bit resistance is small, so the reaction only occurs in 42. Compound 2under acidic conditions TBS protection is removed everolimus.

PATENT

https://patents.google.com/patent/WO2016020664A1/en

Everolimus (RAD-001) is the 40-O- 2-hydroxyethyl)-rapamycin of formula (I),

Figure imgf000002_0001

It is a derivative of sirolimus of formula III),

Figure imgf000002_0002

and works similarly to sirolimus as an inhibitor of mammalian target of rapamycin (mTOR). Everolimus is currently used as an immunosuppressant to prevent rejection of organ transplants and treatment of renal cell cancer and other tumours. It is marketed by Novartis under the tradenames Zortress™ (USA) and Certican™ (Europe and other countries) in transplantation medicine, and Afinitor™ in oncology.

Trisubstituted silyloxyethyltrifluoromethane sulfonates (triflates) of the general formula (IV),

Figure imgf000003_0001

wherein R2, R3 are independently a straight or branched alkyl group, for example C^-Cw alkyl, and/or an aryl group, for example a phenyl group, are important intermediates useful in the synthesis of everolimus.

Everolimus and its process for manufacture using the intermediate 2-(t-butyldimethyl silyl) oxyethyl triflate of formula (IVA),

Figure imgf000003_0002

was first described in US Patent Number 5,665,772. The overall reaction is depicted in Scheme I.

Sche

Figure imgf000004_0001

Everolimus (I)

For the synthesis, firstly sirolimus of formula (III) and 2-(t-butyldimethylsilyl)oxyethyl triflate of formula (IVA) are reacted in the presence of 2,6-Lutidine in toluene at around 60°C to obtain the corresponding 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl rapamycin of formula (I la), which is then deprotected in aqueous hydrochloric acid and converted into crude everolimus [40-O-(2- Hydroxy)ethyl rapamycin] of formula (I). However, this process results in the formation of impure everolimus, which requires purification by column chromatography. The process results in very poor overall yield and purity and thereby the process is not suitable for the commercial scale production of everolimus.

Moenius et al. (I. Labelled Cpd. Radiopharm. 43, 1 13-120 (2000) have disclosed a process to prepare C-14 labelled everolimus using the diphenyltert-butylsilyloxy-protective group of formula (IV B),

Figure imgf000005_0001

as the alkylation agent. The overall yield reported was 25%. International patent application, publication number WO 2012/103960 discloses the preparation of everolimus using the alkylating agent 2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl triflate of formula (IVC),

Figure imgf000005_0002

wherein the overall yield reported is 52.54%. The process involves a derivatization method based on the reaction of the triflate (IV) with a derivatization agent, which preferably is a secondary aromatic amine, typically N-methylaniline.

International patent application, publication number WO 2012/103959 also discloses the preparation of everolimus using the alkylating agent of formula (IVC). The process is based on a reaction of rapamycin with the compound of formula (IVC) in the presence of a base (such as an aliphatic tertiary amine) to form 40-O-2-(t-hexyldimethylsiloxy)ethylrapamycin, which is subsequently deprotected under acidic conditions to obtain everolimus. European Patent Number 1518517B discloses a process for the preparation of everolimus which employs the triflate compound of formula (IVA), 2-(t-butyldimethyl silyl) oxyethyl triflate. The disclosed process for preparing the compound of formula (IVA) involves a flash chromatography purification step. The compounds of formula (IV) are key intermediates in the synthesis of everolimus. However, they are highly reactive and also very unstable, and their use often results in decomposition during reaction with sirolimus. This is reflected by the fact that the yields of the reaction with sirolimus are very low and the compounds of formula (IV) are charged in high molar extent. Thus it is desirable to develop a process to stabilize compounds of formula (IV) without loss of reactivity

 Example 1 :

Step 1 : Preparation of protected everolimus (TBS-everoismus) of formula (Ma) using metal salt, wherein “Pg” is t-butyldimethylsilyl t-butyldimethylsilyloxy ethanol, of formula (VA) (2.8g, 0.016mol) was dissolved in dichloromethane (DCM) (3 vol) and to this 2,6-Lutidine (3.50 g, 0.0327 mol) was added and the mixture was cooled to -40°C. Thereafter, trifluoromethane sulfonic anhydride (3.59ml, 0.021 mol) was added drop-wise. The mixture was maintained at -40°C for 30 minutes. Sirolimus (0.5g, 0.00054mol) was taken in another flask and dissolved in DCM (1 ml). To this sirolimus solution, silver acetate (0.018g, 0.000109mol) was added and cooled to -40°C. The earlier cooled triflate solution was transferred in 3 lots to the sirolimus solution maintaining temperature at -40°C. The reaction mixture was stirred at -40°C further for 15min before which it was slowly warmed to 0°C and further to RT. The reaction mixture was then warmed to 40°C and maintained at this temperature for 3 hours. The reaction was monitored by TLC. On completion of reaction, the reaction mixture was diluted with DCM and washed with water and brine. The organic layer was dried over anhydrous sodium sulphate and solvent was removed by vacuum distillation to obtain the title compound, which was directly used in the next step. HPLC product purity: 60%-85%.

Step 2: Preparation of everolimus of formula (I) Protected everolimus of formula (I la) obtained in step 1 was dissolved in methanol (10 volumes) and chilled to 0-5° C. To this solution was added drop wise, a solution of 1 N HCI. The pH of the reaction was maintained between 1-3. The temperature of the reaction mixture was raised to 25° C and stirred for 1 hour. After completion of reaction, the reaction mixture was diluted with water (15 volumes) and extracted in ethyl acetate (2X20 volumes). The organic layers were combined and washed with brine, dried over sodium sulphate. The organic layer was distilled off under reduced pressure at 30-35° C, to obtain a crude everolimus (0.8 g). The crude everolimus was further purified by preparative HPLC to yield everolimus of purity >99%.

Example 2:

Step 1 : Preparation of TBS-everoiimus of formula (Ma) without using metal salt, wherein “Pg” is t-butyldimethylsilyl t-butyldimethylsilyloxy ethanol, of formula (VA) (2.8g, 0.016mol) was dissolved in DCM (3 vol) and to this 2,6-Lutidine (3.50 g, 0.0327 mol) was added and the mixture was cooled to -40°C. Thereafter, trifluoromethane sulfonic anhydride (3.59ml, 0.021 mol) was added drop-wise. The mixture was maintained at -40°C for 30 minutes. Sirolimus (0.5g, 0.00054mol) was taken in another flask and dissolved in DCM (1 ml). The solution was cooled to -40°C. The earlier cooled triflate solution was transferred in 3 lots to the sirolimus solution maintaining temperature at -40°C. The reaction mixture was stirred at -40°C further for 15min before which it was slowly warmed to 0°C and further to RT. The reaction mixture was then warmed to 40°C and maintained at this temperature for 3 hours. On completion of reaction, the reaction mixture was diluted with DCM and washed with water and brine. The organic layer was dried over anhydrous sodium sulphate and solvent was removed by vacuum distillation to obtain the title compound, which was directly used in next step. HPLC purity: 10%-20%.

Step 2: Preparation of everolimus of formula (I)

Protected everolimus of formula (I la) obtained in step 1 was dissolved in methanol (10 volumes) and chilled to 0-5° C. To this solution was added drop wise, a solution of 1 N HCI. The pH of the reaction was maintained between 1-3. The temperature of the reaction mixture was raised to 25° C and stirred for 1 hour. After completion of reaction, the reaction mixture was diluted with water (15 volumes) and extracted in ethyl acetate (2X20 volumes). The organic layers were combined and washed with brine, dried over sodium sulphate. The organic layer was distilled off under reduced pressure at 30-35° C, to obtain a crude everolimus which was further purified by preparative HPLC. Example 3:

Preparation of crude Everolimus

Step 1 : Preparation of TBS-ethylene glycol of formula (Va)

Ethylene glycol (1.5L, 26.58 mol) and TBDMS-CI (485g, 3.21 mol) were mixed together with stirring and cooled to 0°C. Triethyl amine (679 ml, 4.83 mol) was then added at 0°C in 30-45 minutes. After addition, the reaction was stirred for 12 hours at 25-30°C for the desired conversion. After completion of reaction, the layers were separated and the organic layer (containing TBS- ethylene glycol) was washed with water (1 L.x2) and brine solution (1 L). The organic layer was then subjected to high vacuum distillation to afford 350g of pure product.

Step 2: Preparation of TBS-glycol-Triflate of formula (IVa)

The reaction was carried out under a nitrogen atmosphere. TBS- ethylene glycol prepared as per step 1 (85.10g, 0.48 mol) and 2, 6-Lutidine (84.28ml, 0.72 mol) were stirred in n-heptane (425ml) to give a clear solution which was then cooled to -15 to – 25°C. Trif!uoromethanesulfonic anhydride (Tf20) (99.74 ml, 0.590 mol) was added drop-wise over a period of 45 minutes to the n-heptane solution (white precipitate starts to form immediately) while maintaining the reaction at -15 to – 25°C. The reaction mixture was kept at temperature between -15 to -25°C for 2 hours. The precipitate generated was filtered off. The filtrate was then evaporated up to ~2 volumes with respect to TBS-ethyiene glycol (~200 ml).

Step 3: Preparation of TBS-evero!imus of formula (Ha)

30g of sirolimus (0,0328 mo!) and toluene (150m!) were stirred together and the temperature was slowly raised to 60-65°C. At this temperature, a first portion of TBS-g!yco!-triflate prepared as per step 2 (100ml) and 2,6-Lutidine (1 1.45ml, 0.086 moles) were added and stirred for 40 min. Further, a second portion of TBS- glycol-triflate (50mi) and 2, 6-Lutidine (19.45ml, 0.138 mol) were added and the reaction was stirred for another 40 min. This was followed by a third portion of TBS- glycol- triflate (50m!) and 2, 6-Lutidine (19.45ml, 0.138 mol), after which the reaction was stirred for further 90 minutes. The reaction was monitored through HPLC to check the conversion of Sirolimus to TBS-everolimus after each addition of TBS-glycol-trifiate. After completion of the reaction, the reaction mixture was diluted with n-heptane (150mi), cooled to room temperature and stirred for another 60 minutes. The precipitated solids were filtered off and the filtrate was washed with deionized water (450 ml x4) followed by brine solution (450ml). The filtrate was subsequently distilled off to afford TBS-everolimus (60-65g) with 60-70% conversion from sirolimus.

Step 4: Preparation of everolimus of formula (I)

TBS-everolimus (65g) obtained in step 3 was dissolved in 300 mi methanol and cooled to 0°C. 1 N HCI was then added to the methanol solution (pH adjusted to 2-3) and stirred for 2 h. After completion of reaction, toluene (360m!) and deionized wafer (360mi) were added to the reaction mixture and the aqueous layer was separated. The organic layer was washed with brine solution (360ml). The organic layer was concentrated to obtain crude everolimus (39g) with an assay content of 30-35%, HPLC purity of 60-65%.

The crude everolimus purified by chromatography to achieve purity more than 99 %.

Patent

Publication numberPriority datePublication dateAssigneeTitleUS5665772A *1992-10-091997-09-09Sandoz Ltd.O-alkylated rapamycin derivatives and their use, particularly as immunosuppressantsEP1518517A2 *2002-04-242005-03-30Sun Biomedical, Ltd.Drug-delivery endovascular stent and method for treating restenosisWO2012103960A12011-02-042012-08-09Synthon BvProcess for making trisubstituted silyloxyethyl triflatesCN102786534A2012-05-252012-11-21上海现代制药股份有限公司Preparation method of everolimusCN103788114A *2012-10-312014-05-14江苏汉邦科技有限公司Preparation method for everolimusEP3166950A12014-08-042017-05-17Cipla LimitedProcess for the synthesis of everolimus and intermediates thereof 

CN107417718A *2017-08-182017-12-01常州兰陵制药有限公司The preparation method of everolimus intermediateUS9938297B22014-08-042018-04-10Cipia LimitedProcess for the synthesis of everolimus and intermediates thereofCN108676014A *2018-06-152018-10-19国药集团川抗制药有限公司The method for purifying the method for everolimus intermediate and preparing everolimus 

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References

  • a WO 9 409 010 (Sandoz-Erfindungen; 28.4.1994; GB-prior. 9.10.1992).
  • b US 6 277 983 (American Home Products; 21.8.2001; USA-prior. 27.9.2000).
  •  US 6 384 046 (Novartis; 7.5.2002; GB-prior. 27.3.1996).
  •  US 20 040 115 (Univ. of Pennsylvania; 15.1.2004; USA-prior. 9.7.2002).
  • fermentation of rapamycin (sirolimus):
    • Chen, Y. et al.: Process Biochemistry (Oxford, U. K.) (PBCHE5) 34, 4, 383 (1999).
    • The Merck Index, 14th Ed., 666 (3907) (Rahway 2006).
    • US 3 929 992 (Ayerst McKenna & Harrison Ltd.; 30.12.1975; USA-prior. 29.9.1972).
    • WO 9 418 207 (Sandoz-Erfindungen; 18.8.1994; GB-prior. 2.2.1993).
    • EP 638 125 (Pfizer; 17.4.1996; J-prior. 27.4.1992).
    • US 6 313 264 (American Home Products; 6.11.2001; USA-prior. 8.3.1994).

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https://doi.org/10.1039/C7MD00474EIssue 1, 2018


  • MedChemComm

Ascomycins and rapamycins The ascomycin tacrolimus (44, FK-506) and the two rapamycins sirolimus (45, rapamycin) and everolimus (46) are macrolides that contain 21- and 29-membered macrocyclic rings, respectively (Figure 7).[3] Their MWs range from just over 800 Da for tacrolimus (44) to >900 Da for sirolimus (45) and everolimus (46) and they have >10 HBAs. Like other natural product derived drugs in bRo5 space, they are above average complexity (SMCM 119–134) due to their 14–15 chiral centres. All three are immunosuppressants that are mainly used to prevent rejection of transplanted organs. They bind to overlapping, but slightly different parts of a shallow pocket at the surface of the immunophilin FK506 binding protein (FKBP12, Figure 8 A). Whereas tacrolimus (44) only binds in the pocket on FKBP12 (Figure 8 B),[67] sirolimus (45) and everolimus (46) promote binding of mammalian target of rapamycin (mTOR) so that they bind in a groove formed by FKBP12 and mTOR (Figure 8 C).[68] The complex between tacrolimus (44) and FKBP12 inhibits calcineurin, which results in reduced production of interleukin-2 and inactivation of T cells. Formation of the ternary complexes between FKBP12, sirolimus (45) [or everolimus (46)] and mTOR inhibits mTOR, which arrests growth of T lymphocytes by reducing their sensitivity to interleukin 2. Both tacrolimus (44) and sirolimus (45) have low (15–20 %) and variable bioavailabilities, whereas the bioavailability of everolimus (46) has been increased somewhat as compared to sirolimus (45).[3] Tacrolimus (44) was isolated from Streptomyces tsukubaensis in 1987,[69, 70] while sirolimus (45) was first identified from a Streptomycete strain found in a soil sample from Easter Island.[71] Later it was also isolated from fermentation of another Streptomycete strain.[72, 73] Both drugs are now produced through fermentation.[74, 75] Sirolimus suffers from low bioavailability as well as toxicity, and semi-synthetic derivatives were therefore prepared to minimise these issues. This led to the discovery of everolimus (46), synthesised by selective alkylation of one of the two secondary hydroxyl groups of sirolimus (45) with 2-(tert-butyldimethylsilyl)oxyethyltriflate followed by silyl ether deprotection with HCl (Scheme 8).[76, 77]

str1

Figure 7. Structures of the ascomycin tacrolimus (44) and the rapamycins sirolimus (45) and everolimus (46) that are used mainly to prevent rejection of organ transplants.

str1

[67] G. D. Van Duyne, R. F. Standaert, P. A. Karplus, S. L. Schreiber, J. Clardy, Science 1991, 252, 839 – 842. [68] A. M. Marz, A.-K. Fabian, C. Kozany, A. Bracher, F. Hausch, Mol. Cell. Biol. 2013, 33, 1357 – 1367.

[69] T. Kino, H. Hatanaka, M. Hashimoto, M. Nishiyama, T. Goto, M. Okuhara, M. Kohsaka, H. Aoki, H. Imanaka, J. Antibiot. 1987, 40, 1249 – 1255. [70] H. Tanaka, A. Kuroda, H. Marusawa, H. Hatanaka, T. Kino, T. Goto, M. Hashimoto, T. Taga, J. Am. Chem. Soc. 1987, 109, 5031 – 5033. [71] C. Vzina, A. Kudelski, S. N. Sehgal, J. Antibiot. 1975, 28, 721 – 726. [72] S. N. Sehgal, H. Baker, C. Vzina, J. Antibiot. 1975, 28, 727 – 732. [73] S. N. Sehgal, T. M. Blazekovic, C. Vzina, 1975, US3929992A. [74] C. Barreiro, M. Mart nez-Castro, Appl. Microbiol. Biotechnol. 2014, 98, 497 – 507. [75] S. R. Park, Y. J. Yoo, Y.-H. Ban, Y. J. Yoon, J. Antibiot. 2010, 63, 434 – 441. [76] F. Navarro, S. Petit, G. Stone, 2007, US20020032213A1. [77] S. Cottens, R. Sedrani, 1997, US5665772A.

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Ferreting out why some cancer drugs struggle to shrink tumors

Study shows how stopping one enzyme could help drugs treat an important class of cancers more effectively

by Stu Borman

JUNE 27, 2018 | APPEARED IN VOLUME 96, ISSUE 27

In several types of cancer, including most cases of breast cancer, a cell-signaling network called the PI3K pathway is overactive. Drug designers have tried to quiet this pathway to kill cancer, but they haven’t had much success and, more frustratingly, haven’t understood why the problem is so hard to solve.
09627-leadcon-everolimus.jpg

“There have been more than 200 clinical trials with experimental drugs that target the PI3K pathway, and probably more than $1 billion invested,” says Sourav Bandyopadhyay of the University of California, San Francisco. Just a handful of drugs have been approved by the U.S. FDA and one, Novartis’s Afinitor (everolimus), deters cancer growth but doesn’t shrink tumors, and it prolongs patient survival only a few months.

Bandyopadhyay, his UCSF colleague John D. Gordan, and coworkers used a proteomics approach to ferret out why previous attempts to target the PI3K pathway have had limited success and, using that information, devised and tested a possible fix (Nat. Chem. Biol. 2018, DOI: 10.1038/s41589-018-0081-9).

The stubborn pathway involves a series of kinases—enzymes that modify other proteins by adding phosphate groups—starting with one called PI3K. Overactivation of the pathway produces the transcription factor MYC, which turns on protein synthesis and can spark cancer growth.

The UCSF team used kinase-affinity beads and tandem mass spectrometry to survey all kinases active in breast cancer cells before and after treatment with a variety of cancer drugs. The team studied this so-called kinome to look for kinases associated with the cells’ tendency to resist drug treatments.

The researchers found that a kinase called AURKA undermines everolimus and other pathway-targeted drugs by reversing their effects. While the drugs try to turn off the PI3K pathway, AURKA, activated separately by other pathways, keeps the PI3K pathway turned on. To add insult to injury, MYC boosts AURKA production, maintaining a plentiful supply of the drug spoiler.

09627-leadcon-MLN8237.jpg

When the researchers coadministered everolimus with the AURKA inhibitor MLN8237, also called alisertib, everolimus could inhibit the PI3K pathway as it was designed to do, without interference. The combination treatment killed most types of cancer cells in culture and shrank tumors in mice with breast cancer, whereas everolimus alone permitted slow tumor growth to continue.

References

Links
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Further reading

  • Sedrani R, Cottens S, Kallen J, Schuler W (August 1998). “Chemical modification of rapamycin: the discovery of SDZ RAD”. Transplantation Proceedings30 (5): 2192–4. doi:10.1016/S0041-1345(98)00587-9PMID 9723437.

External links

Clinical data
PronunciationEverolimus /ˌɛvəˈroʊləməs/
Trade namesAfinitor, Zortress
Other names42-O-(2-hydroxyethyl)rapamycin, RAD001
AHFS/Drugs.comMonograph
MedlinePlusa609032
License dataEU EMAby INNUS DailyMedEverolimusUS FDAEverolimus
Pregnancy
category
AU: C[1]
Routes of
administration
By mouth
ATC codeL01EG02 (WHOL04AA18 (WHO)
Legal status
Legal statusUS: ℞-onlyEU: Rx-onlyIn general: ℞ (Prescription only)
Pharmacokinetic data
Elimination half-life~30 hours[2]
Identifiers
showIUPAC name
CAS Number159351-69-6 
PubChem CID6442177
DrugBankDB01590 
ChemSpider21106307 
UNII9HW64Q8G6G
KEGGD02714 
ChEMBLChEMBL1908360 
CompTox Dashboard (EPA)DTXSID0040599 
ECHA InfoCard100.149.896 
Chemical and physical data
FormulaC53H83NO14
Molar mass958.240 g·mol−1
3D model (JSmol)Interactive image
hideSMILESOCCO[C@@H]1CC[C@H](C[C@H]1OC)C[C@@H](C)[C@@H]4CC(=O)[C@H](C)/C=C(\C)[C@@H](O)[C@@H](OC)C(=O)[C@H](C)C[C@H](C)\C=C\C=C\C=C(/C)[C@@H](OC)C[C@@H]2CC[C@@H](C)[C@@](O)(O2)C(=O)C(=O)N3CCCC[C@H]3C(=O)O4
hideInChIInChI=1S/C53H83NO14/c1-32-16-12-11-13-17-33(2)44(63-8)30-40-21-19-38(7)53(62,68-40)50(59)51(60)54-23-15-14-18-41(54)52(61)67-45(35(4)28-39-20-22-43(66-25-24-55)46(29-39)64-9)31-42(56)34(3)27-37(6)48(58)49(65-10)47(57)36(5)26-32/h11-13,16-17,27,32,34-36,38-41,43-46,48-49,55,58,62H,14-15,18-26,28-31H2,1-10H3/b13-11+,16-12+,33-17+,37-27+/t32-,34-,35-,36-,38-,39+,40+,41+,43-,44+,45+,46-,48-,49+,53-/m1/s1 Key:HKVAMNSJSFKALM-GKUWKFKPSA-N 

////////////////  RAD-001,  SDZ RAD, Certican, Novartis, Immunosuppressant, Everolimus, Afinitor, эверолимус , إيفيروليموس , 依维莫司 , 

Everolimus.svg

Everolimus

Everolimus

159351-69-6[RN]
23,27-Epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclohentriacontine-1,5,11,28,29(4H,6H,31H)-pentone, 9,10,12,13,14,21,22,23,24,25,26,27,32,33,34,34a-hexadecahydro-9,27-dihydroxy-3-[(1R)-2-[(1S,3R,4R)-4-(2-hydr oxyethoxy)-3-methoxycyclohexyl]-1-methylethyl]-10,21-dimethoxy-6,8,12,14,20,26-hexamethyl-, (3S,6R,7E,9R,10R,12R,14S,15E,17E,19E,21S,26R,27R,34aS)-
23,27-epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclohentriacontine-1,5,11,28,29(4H,6H,31H)-pentone, 9,10,12,13,14,21,22,23,24,25,26,27,32,33,34,34a-hexadecahydro-9,27-dihydroxy-3-[(1R)-2-[(1S,3R,4R)-4-(2-hydroxyethoxy)-3-methoxycyclohexyl]-1-methylethyl]-10,21-dimethoxy-6,8,12,14,20,26-hexamethyl-, (3S,6R,7E,9R,10R,12R,14S,15E,17E,19E,21S,23S,26R,27R,34aS)-
42-O-(2-Hydroxyethyl)rapamycin

  • Synonyms:RAD-001, SDZ-RAD, Afinitor
  • ATC:L04AA18

Use:immunosuppressantChemical name:42-O-(2-hydroxyethyl)rapamycinFormula:C53H83NO14

  • MW:958.24 g/mol
  • CAS-RN:159351-69-6

EverolimusCAS Registry Number: 159351-69-6CAS Name: 42-O-(2-Hydroxyethyl)rapamycinAdditional Names: 40-O-(2-hydroxyethyl)rapamycinManufacturers’ Codes: RAD-001; SDZ RADTrademarks: Certican (Novartis)Molecular Formula: C53H83NO14Molecular Weight: 958.22Percent Composition: C 66.43%, H 8.73%, N 1.46%, O 23.38%Literature References: Macrolide immunosuppressant; derivative of rapamycin, q.v. Inhibits cytokine-mediated lymphocyte proliferation. Prepn: S. Cottens, R. Sedrani, WO9409010eidem, US5665772 (1994, 1997 both to Sandoz). Pharmacology: W. Schuler et al., Transplantation64, 36 (1997). Whole blood determn by LC/MS: N. Brignol et al., Rapid Commun. Mass Spectrom.15, 898 (2001); by HPLC: S. Baldelli et al.J. Chromatogr. B816, 99 (2005). Clinical pharmacokinetics in combination with cyclosporine: J. M. Kovarik et al., Clin. Pharmacol. Ther.69, 48 (2001). Clinical study in prevention of cardiac-allograft vasculopathy: H. J. Eisen et al.,N. Engl. J. Med.349, 847 (2003). Review: F. J. Dumont et al., Curr. Opin. Invest. Drugs2, 1220-1234 (2001); B. Nashan, Ther. Drug Monit.24, 53-58 (2002).Therap-Cat: Immunosuppressant.Keywords: Immunosuppressant.эверолимус[Russian][INN]إيفيروليموس[Arabic][INN]依维莫司[Chinese][INN]Trade Name:Certican® / Zortress® / Afinitor®MOA:mTOR inhibitorIndication:Rejection of organ transplantation; Renal cell carcinoma; Advanced renal cell carcinoma (RCC); Advanced breast cancer; Pancreatic cancer; Renal angiomyolipoma; Tuberous sclerosis complex (TSC); Rejection in heart transplantation; Rejection of suppression renal transplantation; Subependymal giant cell astrocytoma; neuroendocrine tumors (NET); Advanced gastrointestinal tumorsStatus:ApprovedCompany:Novartis (Originator)Sales:$1,942 Million (Y2015);
$1,902 Million (Y2014);
$1,558 Million (Y2013);
$1,007 Million (Y2012);
$630 Million (Y2011);ATC Code:L04AA18Approved Countries or Area

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2012-08-29New dosage formAfinitor DisperzRenal cell carcinoma , Advanced breast cancer, Pancreatic cancer, Renal angiomyolipoma, Tuberous sclerosis complex (TSC)Tablet, For suspension2 mg/3 mg/5 mgNovartisPriority
2010-04-20New strengthZortressAdvanced renal cell carcinoma (RCC)Tablet0.25 mg/0.5 mg/0.75 mgNovartis 
2009-03-30Marketing approvalAfinitorAdvanced renal cell carcinoma (RCC)Tablet2.5 mg/5 mg/7.5 mg/10 mgNovartisPriority
Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2016-06-02New indicationAfinitorneuroendocrine tumors (NET), Advanced gastrointestinal tumorsTablet Novartis 
2011-09-02Marketing approvalVotubiaAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet2.5 mg/5 mg/10 mgNovartisOrphan; Conditional Approval
2011-09-02Marketing approvalVotubiaAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet, Orally disintegrating2 mg/3 mg/5 mgNovartisOrphan; Conditional Approval
2009-08-03Marketing approvalAfinitorAdvanced breast cancer, Renal cell carcinoma , Pancreatic cancerTablet2.5 mg/5 mg/10 mgNovartis 
Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2011-12-22New indicationCerticanRejection of suppression renal transplantationTablet0.25 mg/0.5 mg/0.75 mgNovartis 
2007-01-26Marketing approvalCerticanRejection in heart transplantationTablet0.25 mg/0.5 mg/0.75 mgNovartis 

More

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2014-02-13Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet2.5 mgNovartis 
2013-01-22Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet10 mgNovartis 
2013-01-22Marketing approval飞尼妥/AfinitorAdvanced renal cell carcinoma (RCC), Subependymal giant cell astrocytomaTablet5 mgNovartis 

More

Approval DateApproval TypeTrade NameIndicationDosage FormStrengthCompanyReview Classification
2003-07-18Marketing approvalCerticanRejection of organ transplantation, Renal cell carcinomaTablet0.25 mg/0.5 mg/0.75 mgNovartis 

clip

Active Substance The active substance Everolimus is a hydroxyethyl derivative of rapamycin, which is a macrolide, isolated from the micro-organism Streptomyces hygroscopicus. The guideline, impurities in new active substances ICHQ 3A (R), does not apply to active substance of fermented origin. Everolimus (INN) or 42-O-(2-hydroxyethyl)-rapamycin (chemical name) or C5 3H8 3N O1 4 has been fully described. The molecule is amorphous and is stabilised with an antioxidant. Its physico-chemical properties including parameters such as solubility, pH, specific rotation, potential polymorphism and potential isomerism have been fully characterised. Everolimus is a white to faintly yellow amorphous powder. It is almost insoluble in water, is unstable at temperatures above 25 °C and is sensitive to light. In addition, possible isomerism has been investigated. Everolimus contains 15 asymmetric carbon atoms and 4 substituted double bonds. The configuration of the asymmetric carbon atoms and the double bonds is guaranteed by the microbial origin of Rapamycin. The configuration is not affected by the chemical synthesis. Polymorphism has been comprehensively discussed and it was demonstrated that the molecule domain remains amorphous.

str1

Synthesis of Everolimus The manufacturing process consists of four main steps, (1) fermentation, (2) extraction of rapamycin from the fermentation broth, (3) chemical modification of rapamycin starting material, (4) purification of crude everolimus and stabilisation with BHT. The choice of the stabilizer has been sufficiently explained and justified by experimental results. Interactions products of Everolimus and the antioxidant were not detected, or were below detection limit. Rapamycin, obtained by a fermentation process, was used as the starting material. Reaction conditions and the necessary in-process controls are described in detail. Adequate specifications for starting materials and isolated intermediates and descriptions of the test procedures have been submitted. Control of the quality of solvents, reagents and auxiliary materials used in the synthesis has been adequately documented. It is stated by the manufacturer of rapamycin solution that no starting material of animal or human origin is used in the fermentation. Elucidation of structure and other characteristics The structure of Everolimus has been fully elucidated using several spectroscopic techniques such as ultraviolet absorption spectroscopy (UV), Infra-red spectroscopy (FT-IR), proton and carbon nuclear magnetic resonance spectroscopy (1 H and 13C NMR), mass spectroscopy, diffractometry (X-ray) and elemental analysis. Related substances An extensive discussion was presented on the related substances. The complex structure of Everolimus allows several possible degradation pathways to occur at various positions of the molecule. Everolimus alone is extremely sensitive to oxidation. By the addition of an antioxidant, the sensitivity to oxidation is significantly reduced (the antioxidant is known to react as a scavenger of peroxide radicals). It is assumed that oxidation of Everolimus proceeds via a radical mechanism. All the requirements set in the current testing instruction valid for Everolimus are justified on the basis of the results obtained during development and manufactured at the production scale.

fda

Everolimus was first approved by Swiss Agency for therapeutic products,Swissmedic on July 18, 2003, then approved by Pharmaceuticals and Medicals Devices Agency of Japan (PMDA) on April 23, 2004, and approved by the U.S. Food and Drug Administration (FDA) on Mar 30, 2009, approved by European Medicine Agency (EMA) on Aug 3, 2009. It was developed and marketed as Certican® by Novartis in SE.

Everolimus is an inhibitor of mammalian target of rapamycin (mTOR). It is indicated for the treatment of renal cell cancer and other tumours and currently used as an immunosuppressant to prevent rejection of organ transplants.

Certican® is available as tablet for oral use, containing 0.25, 0.5 or 0.75 mg of free Everolimus. The recommended dose is 10 mg once daily with or without food for advanced HR+ breast cancer, advanced progressive neuroendocrine tumors, advanced renal cell carcinoma or renal angiomyolipoma with tuberous sclerosis complex.
Everolimus, also known as RAD001, is a derivative of the natural macrocyclic lactone sirolimus with immunosuppressant and anti-angiogenic properties. In cells, everolimus binds to the immunophilin FK Binding Protein-12 (FKBP-12) to generate an immunosuppressive complex that binds to and inhibits the activation of the mammalian Target of Rapamycin (mTOR), a key regulatory kinase. Inhibition of mTOR activation results in the inhibition of T lymphocyte activation and proliferation associated with antigen and cytokine (IL-2, IL-4, and IL-15) stimulation and the inhibition of antibody production.

Everolimus is a medication used as an immunosuppressant to prevent rejection of organ transplants and in the treatment of renal cell cancer and other tumours. Much research has also been conducted on everolimus and other mTOR inhibitors as targeted therapy for use in a number of cancers.[medical citation needed]

It is the 40-O-(2-hydroxyethyl) derivative of sirolimus and works similarly to sirolimus as an inhibitor of mammalian target of rapamycin (mTOR).

It is marketed by Novartis under the trade names Zortress (USA) and Certican (European Union and other countries) in transplantation medicine, and as Afinitor (general tumours) and Votubia (tumours as a result of TSC) in oncology. Everolimus is also available from Biocon, with the brand name Evertor.

Medical uses

Everolimus is approved for various conditions:

  • Advanced kidney cancer (US FDA approved in March 2009)[3]
  • Prevention of organ rejection after renal transplant(US FDA April 2010)[4]
  • Subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis (TS) in patients who are not suitable for surgical intervention (US FDA October 2010)[5]
  • Progressive or metastatic pancreatic neuroendocrine tumors not surgically removable (May 2011)[6]
  • Breast cancer in post-menopausal women with advanced hormone-receptor positive, HER2-negative type cancer, in conjunction with exemestane (US FDA July 2012)[7]
  • Prevention of organ rejection after liver transplant(Feb 2013)
  • Progressive, well-differentiated non-functional, neuroendocrine tumors (NET) of gastrointestinal (GI) or lung origin with unresectable, locally advanced or metastatic disease (US FDA February 2016).[8]
  • Tuberous sclerosis complex-associated partial-onset seizures for adult and pediatric patients aged 2 years and older. (US FDA April 2018).[9]

UK National Health Service

NHS England has been criticised for delays in deciding on a policy for the prescription of everolimus in the treatment of Tuberous Sclerosis. 20 doctors addressed a letter to the board in support of the charity Tuberous Scelerosis Association saying ” around 32 patients with critical need, whose doctors believe everolimus treatment is their best or only option, have no hope of access to funding. Most have been waiting many months. Approximately half of these patients are at imminent risk of a catastrophic event (renal bleed or kidney failure) with a high risk of preventable death.”[10] In May 2015 it was reported that Luke Henry and Stephanie Rudwick, the parents of a child suffering from Tuberous Sclerosis were trying to sell their home in Brighton to raise £30,000 to pay for treatment for their daughter Bethany who has tumours on her brain, kidneys and liver and suffers from up to 50 epileptic fits a day.[11]

Clinical trials

As of October 2010, Phase III trials are under way in gastric cancerhepatocellular carcinoma, and lymphoma.[12] The experimental use of everolimus in refractory chronic graft-versus-host disease was reported in 2012.[13]

Interim phase III trial results in 2011 showed that adding Afinitor (everolimus) to exemestane therapy against advanced breast cancer can significantly improve progression-free survival compared with exemestane therapy alone.[14]

A study published in 2012, shows that everolimus sensitivity varies between patients depending on their tumor genomes.[15] A group of patients with advanced metastasic bladder carcinoma (NCT00805129) [16] treated with everolimus revealed a single patient who had a complete response to everolimus treatment for 26 months. The researchers sequenced the genome of this patient and compared it to different reference genomes and to other patients’ genomes. They found that mutations in TSC1 led to a lengthened duration of response to everolimus and to an increase in the time to cancer recurrence. The mutated TSC1 apparently had made these tumors vulnerable to treatment with everolimus.[medical citation needed]

phase 2a randomized, placebo-controlled everolimus clinical trial published in 2014 showed that everolimus improved the response to an influenza vaccine by 20% in healthy elderly volunteers.[17] A phase 2a randomized, placebo-controlled clinical trial published in 2018 showed that everolimus in combination with dactolisib decreased the rate of reported infections in an elderly population.[17]

Mechanism

Compared with the parent compound rapamycin, everolimus is more selective for the mTORC1 protein complex, with little impact on the mTORC2 complex.[18] This can lead to a hyper-activation of the kinase AKT via inhibition on the mTORC1 negative feedback loop, while not inhibiting the mTORC2 positive feedback to AKT. This AKT elevation can lead to longer survival in some cell types.[medical citation needed] Thus, everolimus has important effects on cell growth, cell proliferation and cell survival.

mTORC1 inhibition by everolimus has been shown to normalize tumor blood vessels, to increase tumor-infiltrating lymphocytes, and to improve adoptive cell transfer therapy.[19]

Additionally, mTORC2 is believed to play an important role in glucose metabolism and the immune system, suggesting that selective inhibition of mTORC1 by drugs such as everolimus could achieve many of the benefits of rapamycin without the associated glucose intolerance and immunosuppression.[18]

TSC1 and TSC2, the genes involved in tuberous sclerosis, act as tumor suppressor genes by regulating mTORC1 activity. Thus, either the loss or inactivation of one of these genes lead to the activation of mTORC1.[20]

Everolimus binds to its protein receptor FKBP12, which directly interacts with mTORC1, inhibiting its downstream signaling. As a consequence, mRNAs that code for proteins implicated in the cell cycle and in the glycolysis process are impaired or altered, and tumor growth is inhibited.[20]

Adverse reactions

A trial using 10 mg/day in patients with NETs of GI or lung origin reported “Everolimus was discontinued for adverse reactions in 29% of patients and dose reduction or delay was required in 70% of everolimus-treated patients. Serious adverse reactions occurred in 42% of everolimus-treated patients and included 3 fatal events (cardiac failure, respiratory failure, and septic shock). The most common adverse reactions (incidence greater than or equal to 30%) were stomatitis, infections, diarrhea, peripheral edema, fatigue and rash. The most common blood abnormalities found (incidence greater than or equal to 50%) were anemia, hypercholesterolemia, lymphopenia, elevated aspartate transaminase (AST) and fasting hyperglycemia.”.[8]

Role in heart transplantation

Everolimus may have a role in heart transplantation, as it has been shown to reduce chronic allograft vasculopathy in such transplants. It also may have a similar role to sirolimus in kidney and other transplants.[21]

Role in liver transplantation

Although, sirolimus had generated fears over use of m-TOR inhibitors in liver transplantation recipients, due to possible early hepatic artery thrombosis and graft loss, use of everolimus in the setting of liver transplantation is promising. Jeng et al.,[22] in their study of 43 patients, concluded the safety of everolimus in the early phase after living donor liver transplantation. In their study, no hepatic artery thrombosis or wound infection was noted. Also, a possible role of everolimus in reducing the recurrence of hepatocellular carcinoma after liver transplantation was correlated. A target trough level of 3 ng/mL at 3 months was shown to be beneficial in recipients with pre-transplant renal dysfunction. In their study, 6 of 9 renal failure patients showed significant recovery of renal function, whereas 3 showed further deterioration, one of whom required hemodialysis.[23] Recently published report by Thorat et al. showed a positive impact on hepatocellular carcinoma (HCC) when everolimus was used as primary immunosuppression starting as early as first week after living donor liver transplantation (LDLT) surgery.[24] In their retrospective and prospective analysis at China Medical University Hospital in Taiwan, the study cohort (n=66) was divided in two groups depending upon the postoperative immunosuppression. Group A: HCC patients that received Everolimus + Tacrolimus based immunosuppressive regimen (n=37). Group B: HCC patients that received standard Tacrolimus based immunosuppressive regimen without everolimus (n=29). The target trough level for EVR was 3 to 5 ng/ml while for TAC it was 8–10 ng/ml. The 1-year, 3-year and 4-year overall survival achieved for Group A patients (Everolimus group) was 94.95%, 86.48% and 86.48%, respectively while for Group B patients it was 82.75%, 68.96%, and 62.06%, respectively (p=0.0217). The first 12-month report of ongoing Everolimus multicenter prospective trial in LDLT (H2307 trial), Jeng LB et al. have shown a 0% recurrence of HCC in everolimus group at 12 months.[25] Jeng LB concluded that an early introduction of everolimus + reduced tacrolimus was non-inferior to standard tacrolimus in terms of efficacy and renal function at 12 months, with HCC recurrence only in tacrolimus control patients.

Use in vascular stents

Everolimus is used in drug-eluting coronary stents as an immunosuppressant to prevent restenosis. Abbott Vascular produce an everolimus-eluting stent (EES) called Xience Alpine. It utilizes the Multi-Link Vision cobalt chromium stent platform and Novartis’ everolimus. The product is widely available globally including the US, the European Union, and Asia-Pacific (APAC) countries. Boston Scientific also market EESes, recent offerings being Promus Elite and Synergy.[citation needed]

Use in aging

Inhibition of mTOR, the molecular target of everolimus, extends the lifespan of model organisms including mice,[26] and mTOR inhibition has been suggested as an anti-aging therapy. Everolimus was used in a clinical trial by Novartis, and short-term treatment was shown to enhance the response to the influenza vaccine in the elderly, possible by reversing immunosenescence.[27] Everolimus treatment of mice results in reduced metabolic side effects compared to sirolimus.[18]Route 1

Reference:1. US5665772A.

2. Drug. Future 199924, 22-29.Route 2

Reference:1. WO2014203185A1.Route 3

Reference:1. WO2012103959A1.Route 4

Reference:1. CN102731527A.

SYN

Synthetic Reference

Wang, Feng. Everolimus intermediate and preparation method thereof. Assignee Shanghai Institute of Pharmaceutical Industry, Peop. Rep. China; China State Institute of Pharmaceutical Industry. CN 109776570. (2019).

SYN 2

str1

Synthetic Reference

Polymer compositions containing a macrocyclic triene compound; Shulze, John E.; Betts, Ronald E.; Savage, Douglas R.; Assignee Sun Bow Co., Ltd., Bermuda; Sun Biomedical Ltd. 2003; Patent Information; Nov 06, 2003; WO 2003090684 A2

SYN 3

str1

Synthetic Reference

Wang, Feng. Everolimus intermediate and preparation method thereof. Assignee Shanghai Institute of Pharmaceutical Industry, Peop. Rep. China; China State Institute of Pharmaceutical Industry. CN 109776570. (2019).

SYN 4

str1

Synthetic Reference

Zabudkin, Oleksandr; Schickaneder, Christian; Matviienko, Iaroslav; Sypchenko, Volodymyr. Method for the synthesis of rapamycin derivatives. Assignee Synbias Pharma AG, Switz. EP 3109250. (2016).

SYN 5

str1

Synthetic Reference

Lu, Shiyong; Zhang, Xiaotian; Chen, Haohan; Ye, Weidong. Preparation of sirolimus 40-ether derivative. Assignee Zhejiang Medicine Co., Ltd. Xinchang Pharmaceutical Factory, Peop. Rep. China. CN 105237549. (2016).

SYN 6

str1

Synthetic Reference

Seo, Jeong U.; Ham, Yun Beom; Kang, Heung Mo; Lee, Gwang Mu; Kim, In Gyu; Kim, Jeong Jin; Park, Ji Su. Preparation of everolimus and synthetic intermediate thereof. Assignee CKD Bio Corp., S. Korea. KR 1529963 (2015).

SYN

EP 0663916; EP 0867438; JP 1996502266; JP 1999240884; US 5665772; WO 9409010

Alkylation of rapamycin (I) with 2-(tert-butyldimethylsilyloxy)ethyl triflate (II) by means of 2,6-lutidine in hot toluene gives the silylated target compound (III), which is deprotected by means of 1N HCl in methanol.

SYN

J Label Compd Radiopharm 1999,42(1),29

The compound has been obtained biosynthetically by an optimized fermentation process using Streptomyces hygroscopicus mutant RSH 1701 with a complex culture medium were [14C]-labeled (1R,3R,4R)-2,3-dichydroxycyclo-hexanecarboxylic acid (I) and [14C]-labeled (S)-pipecolic acid (II) have been added. This fermentation process yielded [14C]-labeled rapamycin (III), which was finally selectively O-alkylated at the C-40 position with monosilylated ethylene glycol triflate in DMSO/dimethoxyethane.

SYN

The reaction of the labeled acylated (+)-bornane-10,2-sultam (IV) with triethyl phosphite gives the phosphonate (V), which is treated with paraformaldehyde, galvinoxyl and K2CO3 yielding the acrylate derivative (VI). The cyclization of (VI) with butadiene (VII) by means of diethylaluminum chloride and galvinoxyl (as radical scavenger) affords the cyclohexene-carboxamide derivative (VIII), which is hydrolyzed with LiOH in THF/water giving the (1R)-3-cyclohexenecarboxylic acid (IX). The oxidation of (IX) with m-chloroperbenzoic acid and triethylamine in CCl4 yielded regioselectively the hydroxylactone (X), which is finally hydrolyzed with HCl to the labeled intermediate (I).

SYN

The reaction of the labeled acylated (-)-bornane-10,2-sultam (XI) with benzophenone imine (XII) gives the glycylsultam derivative (XIII), which is alkylated with 4-iodobutyl chloride (XIV) by means of butyllithium and DMPU in THF yielding intermediate (XV). The selective hydrolysis of (XV) with HCl affords the omega-chloro-L-norleucine derivative (XVI), which is cyclized by means of tetrabutylammonium fluoride and DIEA in hot acetonitrile giving the (2S)-piperidyl derivative (XVII). Finally, this compound is hydrolyzed with LiOH in THF/water to the labeled intermediate (II).

clipRapamycin is a known macrolide antibiotic produced by Streptomvces hvgroscopicus. having the structure depicted in Formula A:

Figure imgf000003_0001

See, e.g., McAlpine, J.B., et al., J. Antibiotics (1991) 44: 688; Schreiber, S.L., et al., J. Am. Chem. Soc. (1991) J_13: 7433‘- US Patent No. 3 929 992. Rapamycin is an extremely potent immunosuppressant and has also been shown to have antitumor and antifungal activity. Its utility as a pharmaceutical, however, is restricted by its very low and variable bioavailabiiity as well as its high toxicity. Moreover, rapamycin is highly insoluble, making it difficult to formulate stable galenic compositions.

Everolimus, 40-O-(2-hydroxyethyl)-rapamycin of formula (1) is a synthetic derivative of rapamycin (sirolimus) of formula (2), which is produced by a certain bacteria strain and is also pharmaceutically active.

Figure imgf000002_0002

(1)                                                                                                               (2)

Everolimus is marketed under the brand name Certican for the prevention of rejection episodes following heart and kidney transplantation, and under the brand name Afinitor for treatment of advanced kidney cancer.

Due to its complicated macrolide chemical structure, everolimus is, similarly as the parent rapamycin, an extremely unstable compound. It is sensitive, in particular, towards oxidation, including aerial oxidation. It is also unstable at temperatures higher than 25°C and at alkaline pH.

Everolimus and a process of making it have been disclosed in WO 94/09010

Synthesis

Alkylation of rapamycin (I) with 2-(tert-butyldimethylsilyloxy)ethyl triflate (II) by means of 2,6-lutidine in hot toluene gives the silylated target compound (III), which is deprotected by means of 1N HCl in methanol (1). (Scheme 21042401a) Manufacturer Novartis AG (CH). References 1. Cottens, S., Sedrani, R. (Sandoz-Refindungen VmbH; Sandoz-Patent GmbH; Sandoz Ltd.). O-Alkylated rapamycin derivatives and their use, particularly as immunosuppressants. EP 663916, EP 867438, JP 96502266, US 5665772, WO 9409010.EP 0663916; EP 0867438; JP 1996502266; JP 1999240884; US 5665772; WO 9409010

…………..

SYNTHESIS

https://www.google.com/patents/WO2012103960A1

(US 5,665,772, EP 663916). The process principle is shown in the scheme below, wherein the abbreviation RAP-OH has been used as an abbreviation for the rapamycin structure of formula (2) above, L is a leaving group and P is a trisubstituted silyl group serving as a OH- protective group.

RAP-OH + L-CH2-CH2-0-P — –> RAP-O-CH2-CH2-O-P — – > RAP-O-CH2-CH2-OH

(2)                                                 (4)                                                                 (1)

Specifically, the L- group is a trifluoromethanesulfonate (triflate) group and the protective group P- is typically a tert-butyldimethylsilyloxy- group. Accordingly, the known useful reagent within the above general formula (3) for making everolimus from rapamycin is 2-(tert-butyldimethylsilyloxy)ethyl triflate of formula (3 A):

Figure imgf000003_0001

According to a known synthetic procedure disclosed in Example 8 of WO 94/09010 and in Example 1 of US application 2003/0125800, rapamycin (2) reacts in hot toluene and in the presence of 2,6-lutidine with a molar excess of the compound (3 A), which is charged in several portions, to form the t-butyldimethylsilyl-protected everolimus (4A). This compound is isolated and deprotected by means of IN aqueous HC1 in methanol. Crude everolimus is then purified by column chromatography. Yields were not reported.

Figure imgf000004_0001

(2)                                       (3A)                              (4A)                                (1)

In an article of Moenius et al. (J. Labelled Cpd. Radiopharm. 43, 113-120 (2000)), which used the above process for making C14-labelled and tritiated everolimus, a diphenyl- tert.butylsilyloxy -protective group was used as the alkylation agent of formula (3B).

Figure imgf000004_0002

Only 8% yield of the corresponding compound (4B)

Figure imgf000004_0003

and 21% yield of the compound (1) have been reported.

Little is known about the compounds of the general formula (3) and methods of their preparation. The synthesis of the compound (3 A) was disclosed in Example 1 of US application 2003/0125800. It should be noted that specification of the reaction solvent in the key step B of this synthesis was omitted in the disclosure; however, the data about isolation of the product allow for estimation that such solvent is dichloromethane. Similarly also a second article of Moenius et al. (J. Labelled Cpd. Radiopharm.42, 29-41 (1999)) teaches that dichloromethane is the solvent in the reaction.

It appears that the compounds of formula (3) are very reactive, and thus also very unstable compounds. This is reflected by the fact that the yields of the reaction with rapamycine are very low and the compound (3) is charged in high molar extent. Methods how to monitor the reactivity and/or improve the stability of compounds of general formula (3), however, do not exist.

Thus, it would be useful to improve both processes of making compounds of formula (3) and, as well, processes of their application in chemical synthesis.

xample 6: 40-O-[2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl]rapamycin

In a 100 mL flask, Rapamycin (6 g, 6.56 mmol) was dissolved in dimethoxyethane (4.2 ml) and toluene (24 ml) to give a white suspension and the temperature was raised to 70°C. After 20 min, N,N-diisopropylethylamine (4.56 ml, 27.6 mmol) and 2-((2,3-dimethylbutan-2- yl)dimethylsilyloxy)ethyl trifluoromethanesulfonate (8.83 g, 26.3 mmol) were added in 2 portions with a 2 hr interval at 70°C. The mixture was stirred overnight at room temperature, then diluted with EtOAc (40 ml) and washed with sat. NaHC03 (30 ml) and brine (30 ml). The organic layer was dried with Na2S04, filtered and concentrated. The cmde product was chromatographed on a silica gel column (EtOAc/heptane 1/1 ; yield 4.47 g).

Example 7: 40-O-(2-hydroxyethyl)-rapamycin [everolimus]

In a 100 mL flask, 40-O-[2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl]rapamycin (4.47 g, 4.06 mmol) was dissolved in methanol (20 ml) to give a colorless solution. At 0°C, IN aqueous hydrochloric acid (2.0 ml, 2.0 mmol) was added and the mixture was stirred for 90 min. The reaction was followed by TLC (ethyl acetate/n-heptane 3 :2) and HPLC. Then 20 ml of saturated aqueous NaHC03 were added, followed by 20 ml of brine and 80 ml of ethyl acetate. The phases were separated and the organic layer was washed with saturated aqueous NaCl until pH 6/7. The organic layer was dried by Na2S04, filtered and concentrated to yield 3.3 g of the product.

……………………….

SYNTHESIS

https://www.google.co.in/patents/WO1994009010A1

Example 8: 40-O-(2-Hydroxy)ethyl-rapamycin

a) 40-O-[2-(t-Butyldimethylsilyl)oxy]ethyl-rapamycin

A solution of 9.14 g (10 mmol) of rapamycin and 4.70 mL (40 mmol) of 2,6-lutidine in 30 mL of toluene is warmed to 60°C and a solution of 6.17 g (20 mmol) of 2-(t-butyldimethylsilyl)oxyethyl triflate and 2.35 mL (20 mmol) of 2,6-lutidine in 20 mL of toluene is added. This mixture is stirred for 1.5h. Then two batches of a solution of 3.08 g (10 mmol) of triflate and 1.2 mL (10 mmol) of 2,6-lutidine in 10 mL of toluene are added in a 1.5h interval. After addition of the last batch, stirring is continued at 60°C for 2h and the resulting brown suspension is filtered. The filtrate is diluted with ethyl acetate and washed with aq. sodium bicarbonate and brine. The organic solution is dried over anhydrous sodium sulfate, filtered and concentrated. The residue is purified by column chromatography on silica gel (40:60 hexane-ethyl acetate) to afford 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl-rapamycin as a white solid: 1H NMR (CDCl3) δ 0.06 (6H, s), 0.72 (1H, dd), 0.90 (9H, s), 1.65 (3H, s), 1.75 (3H, s), 3.02 (1H, m), 3.63 (3H, m), 3.72 (3H, m); MS (FAB) m/z 1094 ([M+Na]+), 1022 ([M-(OCH3+H2O)]+).

b) 40-O-(2-Hydroxy)ethyl-rapamycin

To a stirred, cooled (0°C) solution of 4.5 g (4.2 mmol) of 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl-rapamycin in 20 mL of methanol is added 2 mL of IN HCl. This solution is stirred for 2h and neutralized with aq. sodium bicarbonate. The mixture is extracted with three portions of ethyl acetate. The organic solution is washed with aq.

sodium bicarbonate and brine, dried over anhydrous sodium sulfate, filtered and

concentrated. Purification by column chromatography on silica gel (ethyl acetate) gave the title compound as a white solid:1H NMR (CDCl3) δ 0.72 (1H, dd), 1.65 (3H, s), 1.75 (3H, s), 3.13 (5H, s and m), 3.52-3.91 (8H, m); MS (FAB) m/z 980 ([M+Na]+), 926 ([M-OCH3]+), 908 ([M-(OCH3+H2O)]+), 890 ([M-(OCH3+2H2O)]+), 876 ([M-(2CH3OH+OH)]+), 858 ([M-(OCH3+CH3OH+2H2O)]+).

MBA (rel. IC50) 2.2

IL-6 dep. prol. (rel. IC50) 2.8

MLR (rel. IC50) 3.4

…………………..

synthesis

Everolimus (Everolimus) was synthesized by the Sirolimus (sirolimus, also known as rapamycin Rapamycin) ether from. Sirolimus is from the soil bacterium Streptomyces hygroscopicus isolated metabolites. Activation end sirolimus (triflate, Tf) the other end of the protection (t-butyldimethylsilyl, TBS) of ethylene glycol 1 reaction of 2 , because the hydroxyl group 42 hydroxyl site over the 31-bit resistance is small, so the reaction only occurs in 42. Compound 2under acidic conditions TBS protection is removed everolimus.

PATENT

https://patents.google.com/patent/WO2016020664A1/en

Everolimus (RAD-001) is the 40-O- 2-hydroxyethyl)-rapamycin of formula (I),

Figure imgf000002_0001

It is a derivative of sirolimus of formula III),

Figure imgf000002_0002

and works similarly to sirolimus as an inhibitor of mammalian target of rapamycin (mTOR). Everolimus is currently used as an immunosuppressant to prevent rejection of organ transplants and treatment of renal cell cancer and other tumours. It is marketed by Novartis under the tradenames Zortress™ (USA) and Certican™ (Europe and other countries) in transplantation medicine, and Afinitor™ in oncology.

Trisubstituted silyloxyethyltrifluoromethane sulfonates (triflates) of the general formula (IV),

Figure imgf000003_0001

wherein R2, R3 are independently a straight or branched alkyl group, for example C^-Cw alkyl, and/or an aryl group, for example a phenyl group, are important intermediates useful in the synthesis of everolimus.

Everolimus and its process for manufacture using the intermediate 2-(t-butyldimethyl silyl) oxyethyl triflate of formula (IVA),

Figure imgf000003_0002

was first described in US Patent Number 5,665,772. The overall reaction is depicted in Scheme I.

Sche

Figure imgf000004_0001

Everolimus (I)

For the synthesis, firstly sirolimus of formula (III) and 2-(t-butyldimethylsilyl)oxyethyl triflate of formula (IVA) are reacted in the presence of 2,6-Lutidine in toluene at around 60°C to obtain the corresponding 40-O-[2-(t-butyldimethylsilyl)oxy]ethyl rapamycin of formula (I la), which is then deprotected in aqueous hydrochloric acid and converted into crude everolimus [40-O-(2- Hydroxy)ethyl rapamycin] of formula (I). However, this process results in the formation of impure everolimus, which requires purification by column chromatography. The process results in very poor overall yield and purity and thereby the process is not suitable for the commercial scale production of everolimus.

Moenius et al. (I. Labelled Cpd. Radiopharm. 43, 1 13-120 (2000) have disclosed a process to prepare C-14 labelled everolimus using the diphenyltert-butylsilyloxy-protective group of formula (IV B),

Figure imgf000005_0001

as the alkylation agent. The overall yield reported was 25%. International patent application, publication number WO 2012/103960 discloses the preparation of everolimus using the alkylating agent 2-((2,3-dimethylbut-2-yl)dimethylsilyloxy)ethyl triflate of formula (IVC),

Figure imgf000005_0002

wherein the overall yield reported is 52.54%. The process involves a derivatization method based on the reaction of the triflate (IV) with a derivatization agent, which preferably is a secondary aromatic amine, typically N-methylaniline.

International patent application, publication number WO 2012/103959 also discloses the preparation of everolimus using the alkylating agent of formula (IVC). The process is based on a reaction of rapamycin with the compound of formula (IVC) in the presence of a base (such as an aliphatic tertiary amine) to form 40-O-2-(t-hexyldimethylsiloxy)ethylrapamycin, which is subsequently deprotected under acidic conditions to obtain everolimus. European Patent Number 1518517B discloses a process for the preparation of everolimus which employs the triflate compound of formula (IVA), 2-(t-butyldimethyl silyl) oxyethyl triflate. The disclosed process for preparing the compound of formula (IVA) involves a flash chromatography purification step. The compounds of formula (IV) are key intermediates in the synthesis of everolimus. However, they are highly reactive and also very unstable, and their use often results in decomposition during reaction with sirolimus. This is reflected by the fact that the yields of the reaction with sirolimus are very low and the compounds of formula (IV) are charged in high molar extent. Thus it is desirable to develop a process to stabilize compounds of formula (IV) without loss of reactivity

 Example 1 :

Step 1 : Preparation of protected everolimus (TBS-everoismus) of formula (Ma) using metal salt, wherein “Pg” is t-butyldimethylsilyl t-butyldimethylsilyloxy ethanol, of formula (VA) (2.8g, 0.016mol) was dissolved in dichloromethane (DCM) (3 vol) and to this 2,6-Lutidine (3.50 g, 0.0327 mol) was added and the mixture was cooled to -40°C. Thereafter, trifluoromethane sulfonic anhydride (3.59ml, 0.021 mol) was added drop-wise. The mixture was maintained at -40°C for 30 minutes. Sirolimus (0.5g, 0.00054mol) was taken in another flask and dissolved in DCM (1 ml). To this sirolimus solution, silver acetate (0.018g, 0.000109mol) was added and cooled to -40°C. The earlier cooled triflate solution was transferred in 3 lots to the sirolimus solution maintaining temperature at -40°C. The reaction mixture was stirred at -40°C further for 15min before which it was slowly warmed to 0°C and further to RT. The reaction mixture was then warmed to 40°C and maintained at this temperature for 3 hours. The reaction was monitored by TLC. On completion of reaction, the reaction mixture was diluted with DCM and washed with water and brine. The organic layer was dried over anhydrous sodium sulphate and solvent was removed by vacuum distillation to obtain the title compound, which was directly used in the next step. HPLC product purity: 60%-85%.

Step 2: Preparation of everolimus of formula (I) Protected everolimus of formula (I la) obtained in step 1 was dissolved in methanol (10 volumes) and chilled to 0-5° C. To this solution was added drop wise, a solution of 1 N HCI. The pH of the reaction was maintained between 1-3. The temperature of the reaction mixture was raised to 25° C and stirred for 1 hour. After completion of reaction, the reaction mixture was diluted with water (15 volumes) and extracted in ethyl acetate (2X20 volumes). The organic layers were combined and washed with brine, dried over sodium sulphate. The organic layer was distilled off under reduced pressure at 30-35° C, to obtain a crude everolimus (0.8 g). The crude everolimus was further purified by preparative HPLC to yield everolimus of purity >99%.

Example 2:

Step 1 : Preparation of TBS-everoiimus of formula (Ma) without using metal salt, wherein “Pg” is t-butyldimethylsilyl t-butyldimethylsilyloxy ethanol, of formula (VA) (2.8g, 0.016mol) was dissolved in DCM (3 vol) and to this 2,6-Lutidine (3.50 g, 0.0327 mol) was added and the mixture was cooled to -40°C. Thereafter, trifluoromethane sulfonic anhydride (3.59ml, 0.021 mol) was added drop-wise. The mixture was maintained at -40°C for 30 minutes. Sirolimus (0.5g, 0.00054mol) was taken in another flask and dissolved in DCM (1 ml). The solution was cooled to -40°C. The earlier cooled triflate solution was transferred in 3 lots to the sirolimus solution maintaining temperature at -40°C. The reaction mixture was stirred at -40°C further for 15min before which it was slowly warmed to 0°C and further to RT. The reaction mixture was then warmed to 40°C and maintained at this temperature for 3 hours. On completion of reaction, the reaction mixture was diluted with DCM and washed with water and brine. The organic layer was dried over anhydrous sodium sulphate and solvent was removed by vacuum distillation to obtain the title compound, which was directly used in next step. HPLC purity: 10%-20%.

Step 2: Preparation of everolimus of formula (I)

Protected everolimus of formula (I la) obtained in step 1 was dissolved in methanol (10 volumes) and chilled to 0-5° C. To this solution was added drop wise, a solution of 1 N HCI. The pH of the reaction was maintained between 1-3. The temperature of the reaction mixture was raised to 25° C and stirred for 1 hour. After completion of reaction, the reaction mixture was diluted with water (15 volumes) and extracted in ethyl acetate (2X20 volumes). The organic layers were combined and washed with brine, dried over sodium sulphate. The organic layer was distilled off under reduced pressure at 30-35° C, to obtain a crude everolimus which was further purified by preparative HPLC. Example 3:

Preparation of crude Everolimus

Step 1 : Preparation of TBS-ethylene glycol of formula (Va)

Ethylene glycol (1.5L, 26.58 mol) and TBDMS-CI (485g, 3.21 mol) were mixed together with stirring and cooled to 0°C. Triethyl amine (679 ml, 4.83 mol) was then added at 0°C in 30-45 minutes. After addition, the reaction was stirred for 12 hours at 25-30°C for the desired conversion. After completion of reaction, the layers were separated and the organic layer (containing TBS- ethylene glycol) was washed with water (1 L.x2) and brine solution (1 L). The organic layer was then subjected to high vacuum distillation to afford 350g of pure product.

Step 2: Preparation of TBS-glycol-Triflate of formula (IVa)

The reaction was carried out under a nitrogen atmosphere. TBS- ethylene glycol prepared as per step 1 (85.10g, 0.48 mol) and 2, 6-Lutidine (84.28ml, 0.72 mol) were stirred in n-heptane (425ml) to give a clear solution which was then cooled to -15 to – 25°C. Trif!uoromethanesulfonic anhydride (Tf20) (99.74 ml, 0.590 mol) was added drop-wise over a period of 45 minutes to the n-heptane solution (white precipitate starts to form immediately) while maintaining the reaction at -15 to – 25°C. The reaction mixture was kept at temperature between -15 to -25°C for 2 hours. The precipitate generated was filtered off. The filtrate was then evaporated up to ~2 volumes with respect to TBS-ethyiene glycol (~200 ml).

Step 3: Preparation of TBS-evero!imus of formula (Ha)

30g of sirolimus (0,0328 mo!) and toluene (150m!) were stirred together and the temperature was slowly raised to 60-65°C. At this temperature, a first portion of TBS-g!yco!-triflate prepared as per step 2 (100ml) and 2,6-Lutidine (1 1.45ml, 0.086 moles) were added and stirred for 40 min. Further, a second portion of TBS- glycol-triflate (50mi) and 2, 6-Lutidine (19.45ml, 0.138 mol) were added and the reaction was stirred for another 40 min. This was followed by a third portion of TBS- glycol- triflate (50m!) and 2, 6-Lutidine (19.45ml, 0.138 mol), after which the reaction was stirred for further 90 minutes. The reaction was monitored through HPLC to check the conversion of Sirolimus to TBS-everolimus after each addition of TBS-glycol-trifiate. After completion of the reaction, the reaction mixture was diluted with n-heptane (150mi), cooled to room temperature and stirred for another 60 minutes. The precipitated solids were filtered off and the filtrate was washed with deionized water (450 ml x4) followed by brine solution (450ml). The filtrate was subsequently distilled off to afford TBS-everolimus (60-65g) with 60-70% conversion from sirolimus.

Step 4: Preparation of everolimus of formula (I)

TBS-everolimus (65g) obtained in step 3 was dissolved in 300 mi methanol and cooled to 0°C. 1 N HCI was then added to the methanol solution (pH adjusted to 2-3) and stirred for 2 h. After completion of reaction, toluene (360m!) and deionized wafer (360mi) were added to the reaction mixture and the aqueous layer was separated. The organic layer was washed with brine solution (360ml). The organic layer was concentrated to obtain crude everolimus (39g) with an assay content of 30-35%, HPLC purity of 60-65%.

The crude everolimus purified by chromatography to achieve purity more than 99 %.

Patent

Publication numberPriority datePublication dateAssigneeTitleUS5665772A *1992-10-091997-09-09Sandoz Ltd.O-alkylated rapamycin derivatives and their use, particularly as immunosuppressantsEP1518517A2 *2002-04-242005-03-30Sun Biomedical, Ltd.Drug-delivery endovascular stent and method for treating restenosisWO2012103960A12011-02-042012-08-09Synthon BvProcess for making trisubstituted silyloxyethyl triflatesCN102786534A2012-05-252012-11-21上海现代制药股份有限公司Preparation method of everolimusCN103788114A *2012-10-312014-05-14江苏汉邦科技有限公司Preparation method for everolimusEP3166950A12014-08-042017-05-17Cipla LimitedProcess for the synthesis of everolimus and intermediates thereof 

CN107417718A *2017-08-182017-12-01常州兰陵制药有限公司The preparation method of everolimus intermediateUS9938297B22014-08-042018-04-10Cipia LimitedProcess for the synthesis of everolimus and intermediates thereofCN108676014A *2018-06-152018-10-19国药集团川抗制药有限公司The method for purifying the method for everolimus intermediate and preparing everolimus 

Enzymes

Synthesis Path

Trade Names

CountryTrade NameVendorAnnotation
DCerticanNovartis ,2004
FCerticanNovartis
ICerticanNovartis
JCerticanNovartis

Formulations

  • tabl. 0.25 mg, 0.5 mg, 0.75 mg

References

  • a WO 9 409 010 (Sandoz-Erfindungen; 28.4.1994; GB-prior. 9.10.1992).
  • b US 6 277 983 (American Home Products; 21.8.2001; USA-prior. 27.9.2000).
  •  US 6 384 046 (Novartis; 7.5.2002; GB-prior. 27.3.1996).
  •  US 20 040 115 (Univ. of Pennsylvania; 15.1.2004; USA-prior. 9.7.2002).
  • fermentation of rapamycin (sirolimus):
    • Chen, Y. et al.: Process Biochemistry (Oxford, U. K.) (PBCHE5) 34, 4, 383 (1999).
    • The Merck Index, 14th Ed., 666 (3907) (Rahway 2006).
    • US 3 929 992 (Ayerst McKenna & Harrison Ltd.; 30.12.1975; USA-prior. 29.9.1972).
    • WO 9 418 207 (Sandoz-Erfindungen; 18.8.1994; GB-prior. 2.2.1993).
    • EP 638 125 (Pfizer; 17.4.1996; J-prior. 27.4.1992).
    • US 6 313 264 (American Home Products; 6.11.2001; USA-prior. 8.3.1994).

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https://doi.org/10.1039/C7MD00474EIssue 1, 2018


  • MedChemComm

Ascomycins and rapamycins The ascomycin tacrolimus (44, FK-506) and the two rapamycins sirolimus (45, rapamycin) and everolimus (46) are macrolides that contain 21- and 29-membered macrocyclic rings, respectively (Figure 7).[3] Their MWs range from just over 800 Da for tacrolimus (44) to >900 Da for sirolimus (45) and everolimus (46) and they have >10 HBAs. Like other natural product derived drugs in bRo5 space, they are above average complexity (SMCM 119–134) due to their 14–15 chiral centres. All three are immunosuppressants that are mainly used to prevent rejection of transplanted organs. They bind to overlapping, but slightly different parts of a shallow pocket at the surface of the immunophilin FK506 binding protein (FKBP12, Figure 8 A). Whereas tacrolimus (44) only binds in the pocket on FKBP12 (Figure 8 B),[67] sirolimus (45) and everolimus (46) promote binding of mammalian target of rapamycin (mTOR) so that they bind in a groove formed by FKBP12 and mTOR (Figure 8 C).[68] The complex between tacrolimus (44) and FKBP12 inhibits calcineurin, which results in reduced production of interleukin-2 and inactivation of T cells. Formation of the ternary complexes between FKBP12, sirolimus (45) [or everolimus (46)] and mTOR inhibits mTOR, which arrests growth of T lymphocytes by reducing their sensitivity to interleukin 2. Both tacrolimus (44) and sirolimus (45) have low (15–20 %) and variable bioavailabilities, whereas the bioavailability of everolimus (46) has been increased somewhat as compared to sirolimus (45).[3] Tacrolimus (44) was isolated from Streptomyces tsukubaensis in 1987,[69, 70] while sirolimus (45) was first identified from a Streptomycete strain found in a soil sample from Easter Island.[71] Later it was also isolated from fermentation of another Streptomycete strain.[72, 73] Both drugs are now produced through fermentation.[74, 75] Sirolimus suffers from low bioavailability as well as toxicity, and semi-synthetic derivatives were therefore prepared to minimise these issues. This led to the discovery of everolimus (46), synthesised by selective alkylation of one of the two secondary hydroxyl groups of sirolimus (45) with 2-(tert-butyldimethylsilyl)oxyethyltriflate followed by silyl ether deprotection with HCl (Scheme 8).[76, 77]

str1

Figure 7. Structures of the ascomycin tacrolimus (44) and the rapamycins sirolimus (45) and everolimus (46) that are used mainly to prevent rejection of organ transplants.

str1

[67] G. D. Van Duyne, R. F. Standaert, P. A. Karplus, S. L. Schreiber, J. Clardy, Science 1991, 252, 839 – 842. [68] A. M. Marz, A.-K. Fabian, C. Kozany, A. Bracher, F. Hausch, Mol. Cell. Biol. 2013, 33, 1357 – 1367.

[69] T. Kino, H. Hatanaka, M. Hashimoto, M. Nishiyama, T. Goto, M. Okuhara, M. Kohsaka, H. Aoki, H. Imanaka, J. Antibiot. 1987, 40, 1249 – 1255. [70] H. Tanaka, A. Kuroda, H. Marusawa, H. Hatanaka, T. Kino, T. Goto, M. Hashimoto, T. Taga, J. Am. Chem. Soc. 1987, 109, 5031 – 5033. [71] C. Vzina, A. Kudelski, S. N. Sehgal, J. Antibiot. 1975, 28, 721 – 726. [72] S. N. Sehgal, H. Baker, C. Vzina, J. Antibiot. 1975, 28, 727 – 732. [73] S. N. Sehgal, T. M. Blazekovic, C. Vzina, 1975, US3929992A. [74] C. Barreiro, M. Mart nez-Castro, Appl. Microbiol. Biotechnol. 2014, 98, 497 – 507. [75] S. R. Park, Y. J. Yoo, Y.-H. Ban, Y. J. Yoon, J. Antibiot. 2010, 63, 434 – 441. [76] F. Navarro, S. Petit, G. Stone, 2007, US20020032213A1. [77] S. Cottens, R. Sedrani, 1997, US5665772A.

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Ferreting out why some cancer drugs struggle to shrink tumors

Study shows how stopping one enzyme could help drugs treat an important class of cancers more effectively

by Stu Borman

JUNE 27, 2018 | APPEARED IN VOLUME 96, ISSUE 27

In several types of cancer, including most cases of breast cancer, a cell-signaling network called the PI3K pathway is overactive. Drug designers have tried to quiet this pathway to kill cancer, but they haven’t had much success and, more frustratingly, haven’t understood why the problem is so hard to solve.
09627-leadcon-everolimus.jpg

“There have been more than 200 clinical trials with experimental drugs that target the PI3K pathway, and probably more than $1 billion invested,” says Sourav Bandyopadhyay of the University of California, San Francisco. Just a handful of drugs have been approved by the U.S. FDA and one, Novartis’s Afinitor (everolimus), deters cancer growth but doesn’t shrink tumors, and it prolongs patient survival only a few months.

Bandyopadhyay, his UCSF colleague John D. Gordan, and coworkers used a proteomics approach to ferret out why previous attempts to target the PI3K pathway have had limited success and, using that information, devised and tested a possible fix (Nat. Chem. Biol. 2018, DOI: 10.1038/s41589-018-0081-9).

The stubborn pathway involves a series of kinases—enzymes that modify other proteins by adding phosphate groups—starting with one called PI3K. Overactivation of the pathway produces the transcription factor MYC, which turns on protein synthesis and can spark cancer growth.

The UCSF team used kinase-affinity beads and tandem mass spectrometry to survey all kinases active in breast cancer cells before and after treatment with a variety of cancer drugs. The team studied this so-called kinome to look for kinases associated with the cells’ tendency to resist drug treatments.

The researchers found that a kinase called AURKA undermines everolimus and other pathway-targeted drugs by reversing their effects. While the drugs try to turn off the PI3K pathway, AURKA, activated separately by other pathways, keeps the PI3K pathway turned on. To add insult to injury, MYC boosts AURKA production, maintaining a plentiful supply of the drug spoiler.

09627-leadcon-MLN8237.jpg

When the researchers coadministered everolimus with the AURKA inhibitor MLN8237, also called alisertib, everolimus could inhibit the PI3K pathway as it was designed to do, without interference. The combination treatment killed most types of cancer cells in culture and shrank tumors in mice with breast cancer, whereas everolimus alone permitted slow tumor growth to continue.

References

Links
  1. Jump up to:a b Use During Pregnancy and Breastfeeding
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  10. ^ Lintern, Shaun (14 April 2015). “Policy delays risk ‘preventable deaths’, doctors warn NHS England”. Health Service Journal. Retrieved 20 April 2015.
  11. ^ “Couple forced to sell home after NHS refuse to fund daughter’s treatment for rare illness”. Daily Express. 11 May 2015. Retrieved 12 May 2015.
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  13. ^ Lutz M, Kapp M, Grigoleit GU, Stuhler G, Einsele H, Mielke S (April 2012). “Salvage therapy with everolimus improves quality of life in patients with refractory chronic graft-versus-host disease” (PDF). Bone Marrow Transplant47 (S1): S410–S411.
  14. ^ “Positive Trial Data Leads Novartis to Plan Breast Cancer Filing for Afinitor by Year End”. 2011.
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  23. ^ Jeng L, Thorat A, Yang H, Yeh C-C, Chen T-H, Hsu S-C. Impact of Everolimus On the Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplantation When Used in Early Stage: A Single Center Prospective Study [abstract]. Am J Transplant. 2015; 15 (suppl 3). http://www.atcmeetingabstracts.com/abstract/impact-of-everolimus-on-the-hepatocellular-carcinoma-recurrence-after-living-donor-liver-transplantation-when-used-in-early-stage-a-single-center-prospective-study/. Accessed 1 September 2015.
  24. ^ Thorat A, Jeng LB, Yang HR, Yeh CC, Hsu SC, Chen TH, Poon KS (November 2017). “Assessing the role of everolimus in reducing hepatocellular carcinoma recurrence after living donor liver transplantation for patients within the UCSF criteria: re-inventing the role of mammalian target of rapamycin inhibitors”Annals of Hepato-Biliary-Pancreatic Surgery21 (4): 205–211. doi:10.14701/ahbps.2017.21.4.205PMC 5736740PMID 29264583.
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Further reading

  • Sedrani R, Cottens S, Kallen J, Schuler W (August 1998). “Chemical modification of rapamycin: the discovery of SDZ RAD”. Transplantation Proceedings30 (5): 2192–4. doi:10.1016/S0041-1345(98)00587-9PMID 9723437.

External links

Clinical data
PronunciationEverolimus /ˌɛvəˈroʊləməs/
Trade namesAfinitor, Zortress
Other names42-O-(2-hydroxyethyl)rapamycin, RAD001
AHFS/Drugs.comMonograph
MedlinePlusa609032
License dataEU EMAby INNUS DailyMedEverolimusUS FDAEverolimus
Pregnancy
category
AU: C[1]
Routes of
administration
By mouth
ATC codeL01EG02 (WHOL04AA18 (WHO)
Legal status
Legal statusUS: ℞-onlyEU: Rx-onlyIn general: ℞ (Prescription only)
Pharmacokinetic data
Elimination half-life~30 hours[2]
Identifiers
showIUPAC name
CAS Number159351-69-6 
PubChem CID6442177
DrugBankDB01590 
ChemSpider21106307 
UNII9HW64Q8G6G
KEGGD02714 
ChEMBLChEMBL1908360 
CompTox Dashboard (EPA)DTXSID0040599 
ECHA InfoCard100.149.896 
Chemical and physical data
FormulaC53H83NO14
Molar mass958.240 g·mol−1
3D model (JSmol)Interactive image
hideSMILESOCCO[C@@H]1CC[C@H](C[C@H]1OC)C[C@@H](C)[C@@H]4CC(=O)[C@H](C)/C=C(\C)[C@@H](O)[C@@H](OC)C(=O)[C@H](C)C[C@H](C)\C=C\C=C\C=C(/C)[C@@H](OC)C[C@@H]2CC[C@@H](C)[C@@](O)(O2)C(=O)C(=O)N3CCCC[C@H]3C(=O)O4
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DETOMIDINE


Detomidine.png

DETOMIDINE1H-Imidazole, 4-[(2,3-dimethylphenyl)methyl]-
4-(2,3-Dimethylbenzyl)-1H-imidazole
507876631-46-4[RN]7N8K34P2XH

  • Molecular FormulaC12H14N2
  • Average mass186.253 Da

UNII-7N8K34P2XHдетомидинديتوميدين地托咪定

Detomidine (hydrochloride) (Domosedan, MPV 253AII, CAS Number: 90038-01-0)

Formal Name5-[(2,3-dimethylphenyl)methyl]-1H-imidazole, monohydrochlorideCAS Number90038-01-0Synonyms

  • Domosedan
  • MPV 253AII

Molecular FormulaC12H14N2 • HClFormula Weight222.7DetomidineCAS Registry Number: 76631-46-4CAS Name: 4-[(2,3-Dimethylphenyl)methyl]-1H-imidazoleAdditional Names: 4-(2¢,3¢-dimethylbenzyl)imidazoleMolecular Formula: C12H14N2Molecular Weight: 186.25Percent Composition: C 77.38%, H 7.58%, N 15.04%Literature References: a2-Adrenoceptor agonist with sedative and analgesic activity. Prepn: A. J. Karjalayne, K. O. A. Kurkela, EP24829eidem,US4443466 (1981, 1984 both to Farmos). Physical studies: E. Laine et al.,Acta Pharm. Suec.20, 451 (1983). Crystal structure: L. H. J. Lajunen et al.,ibid.21, 163 (1984). Pharmacology: R. Virtanen, L. Nyman, Eur. J. Pharmacol.108, 163 (1985); R. Virtanen, E. MacDonald, ibid.115, 277 (1985). Mechanism of action: eidem,J. Vet. Pharmacol. Ther.8, 30 (1985).Properties: Crystals from acetone, mp 114-116°. LD50 i.v. in mice: 35 mg/kg (Karjalayne, Kurkela).Melting point: mp 114-116°Toxicity data: LD50 i.v. in mice: 35 mg/kg (Karjalayne, Kurkela) Derivative Type: HydrochlorideTrademarks: Domosedan (Farmos)Molecular Formula: C12H14N2.HClMolecular Weight: 222.71Percent Composition: C 64.72%, H 6.79%, N 12.58%, Cl 15.92%Properties: Crystals, mp 160°. Converts reversibly to monohydrate at room temp, 80% humidity.Melting point: mp 160° Therap-Cat-Vet: Sedative.

Detomidine is an imidazole derivative and α2-adrenergic agonist,used as a large animal sedative, primarily used in horses. It is usually available as the salt detomidine hydrochloride. It is a prescription medication available to veterinarians sold under the trade name Dormosedan.

Currently, detomidine is only licensed for use in horses in the US but it is also licensed for use in cattle in Europe and Australasia.[1]

Properties

Detomidine is a sedative with analgesic properties.[2] α2-adrenergic agonists produce dose-dependent sedative and analgesic effects, mediated by activation of α2 catecholamine receptors, thus inducing a negative feedback response, reducing production of excitatory neurotransmitters. Due to inhibition of the sympathetic nervous system, detomidine also has cardiac and respiratory effects and an antidiuretic action.[3]

Effects

UsesA profound lethargy and characteristic lowering of the head with reduced sensitivity to environmental stimuli (sound, pain, etc.) are seen with detomidine. A short period of reduced coordination is characteristically followed by immobility and a firm stance with front legs spread. Following administration there is an initial increase in blood pressure, followed by bradycardia and second degree atrioventricular block (this is not pathologic in horses). The horse commonly sweats to excess, especially on the flanks and neck. Other side effects reported include pilo erection (hair standing erect), ataxiasalivation, slight muscle tremors, and (rarely) penile prolapse. 

Sedation and anaesthetic premedication in horses and other large animals, commonly combined with butorphanol for increased analgesia and depth of sedation. In conjunction with ketamine it may also be used for intravenous anaesthesia of short duration.

The drug is normally administered by the intravenous route, and is fastest and most efficient when given intravenously . However, in recalcitrant animals, detomidine may be administered by the intramuscular or sublingual routes. The dose range advised by the manufacturers is 20–40 µg/kg intravenous for moderate sedation, but this dose may need to be higher if given intramuscularly.

When given intravenously, detomidine usually takes effect in 2–5 minutes, and recovery is full within 30–60 minutes. However, this is highly dependent upon the dosage, environment, and the individual animal; some horses are highly resistant to sedation.

Detomidine is a poor premedication when using ketamine as an anesthetic in horses.As detomidine is an arrhythmogenic agent, extreme care should be exercised in horses with cardiac disease, and in the concurrent administration of other arrhythmogenics. The concurrent use of potentiated sulfonamide antibiotics is considered particularly dangerous.

Anesthetic recoveries in horses that have received ketamine following a detomidine premedication are often violent with the horse having multiple failures to stand resulting in trauma to itself. Xylazine is a superior premedication with ketamine resulting in safer recoveries.

PATENT

EP-03782989

Novel crystalline forms of detomidine hydrochloride monohydrate, processes for their preparation and compositions comprising them are claimed. Also claimed is their use as alpha2-adrenoreceptor agonists.

Detomidine hydrochloride (1H imidazole,4-[(2,3-dimethylphenyl)methyl]-hydrochloride (CAS Number: 90038-01-0) is a synthetic alpha 2-adrenoreceptor agonist with sedative and analgesic properties widely used for sedation of large animals like horses and cattle. This substance displays various other pharmacologic effects related to the cardiovascular and respiratory system as well as on muscles. Detomidine hydrochloride is available as a parenteral solution with 10 mg/ml as active ingredient which is indicated for use as a sedative and analgesic to facilitate minor surgical and diagnostic procedures in mature horses and yearlings (e.g. DORMOSEDAN®). Furthermore, detomidine hydrochloride is supplied as an oromucosal (i.e. sublingual) gel (e.g. DORMOSEDAN GEL®) with 7.6 mg/ml as active ingredient which is indicated for sedation and restraint in horses.
Further details regarding the clinical pharmacology and side effects as well as contraindications for this drug substance (i.e. active pharmaceutical ingredient) can be found in: Veterinary Psychopharmacology; Sharon L. et al., 2nd edition (2019), Wiley & Sons (pages 161 – 162). According to these authors detomidine has not been used in humans to date.
Detomidini hydrochloridum ad usum veterinarium is included in the EUROPEAN PHARMACOPOEIA (Ph. Eur. 9.0) but currently not included in the United States Pharmacopoeia (USP). It has to be noted that in the absence of a statement regarding a specific hydrate form, like a degree of hydration or mono-, di-, etc., in the title of the monograph – as is the case for detomidine hydrochloride – the anhydrous form is indicated for this substance.
According to a prior version of the respective monograph, namely Ph. Eur. 8.0, the substance exists as a white or almost white, hygroscopic, crystalline powder. The substance is soluble in water, freely soluble in ethanol (96 %), very slightly soluble in methylene chloride and practically insoluble in acetone. The molecular weight (M r) amounts to 222.7. The melting point (mp) is specified at about 160 °C. In the current monograph (Ph. Eur. 9.0) the content of detomidine hydrochloride is specified at 99.0 % to 101.0 percent (anhydrous substance).

[0003]  In the current monograph (Ph. Eur. 9.0) the content of detomidine hydrochloride is specified at 99.0 % to 101.0 % (anhydrous substance).
The current monograph includes the three following known impurities:

Impurity A: (RS)-(2,3-dimethylphenyl) (1H-imidazol-4-yl)-methanol

Impurity B: (RS)-(1-benzyl-1H-imidazol-5-yl)(2,3-dimethylphenyl)-methanol

Impurity C: 4-[(2,3-dimethylcylohexyl)methyl]-1H-imidazole

The related substances are specified at ≤ 0.20 % for any unspecified impurities and ≤ 0.5 % for total impurities with a reporting threshold of 0.10 %.
The water content of detomidine hydrochloride as determined by Karl Fischer (KF) titration is limited to ≤ 2.0 % for release as well as shelf-life testing. As detomidine hydrochloride is hygroscopic, the compound has to be stored in airtight containers.

[0004]  A synthesis method for detomidine was disclosed in US 4,584,383.
Specific details on the last two steps of a synthesis method for detomidine hydrochloride (including a reaction scheme) were published in Drugs Future 10, 17 (1985).

[0005]  Detomidine hydrochloride is known to exist in two crystalline forms, namely the anhydrous form, as described above, and the monohydrate form B (M r: 240.7, CAS Number: 90038-00-9) which can easily interconvert, depending on ambient temperature and air humidity ( Veldre, K. et al., Eur. Journ. Pharm. 44, 273-280 (2011)). At 80 % air humidity and room temperature the monohydrate is reversibly formed. The theoretical water content of detomidine hydrochloride monohydrate amounts to 7.48 %.

[0006]  To date, all commercially available (i.e. veterinary) drug products (i.e. parenteral solutions and oromucosal gels) only contain the anhydrous form. In general, hygroscopic substances like detomidine hydrochloride tend to absorb moisture so that they have to be protected from a humid environment during production and storage of the drug substance and corresponding drug product to avoid an inacceptable uptake of water. It has to be noted that such uptake during storage will reduce the content of the drug substance so that this would have to be taken into consideration during production of the corresponding drug product, like pharmaceutical preparation.

[0007]  The problem to be solved is to provide a pure and stable active pharmaceutical ingredient (API), namely detomidine hydrochloride monohydrate, that can advantageously be used for the production of pharmaceutical compositions comprising the active pharmaceutical ingredient detomidine hydrochloride.

Example 1

Preparation of detomidine hydrochloride monohydrate (DHM)

[0053]  Detomidine hydrochloride was synthesized starting from 1-benzyl-imidazole-4-carboxyaldehyde and 2,3-dimethylphenlymagnesiumbromide according to the two-step synthesis described in Drugs Future 10, 17 (1985).

[0054]  For the second step of this synthesis (RS)-(3-Benzyl-3 H-imidazol-4-yl)-(2,3-dimethyl-phenyl)-methanol (HCl) was suspended in a mixture of water and hydrochloric acid. The catalyst (i. e. palladium on activated carbon) suspended in demineralized water was added. Hydrogenation (i.e. removal of the benzyl group and reduction of the hydroxyl group with hydrogen (H 2/Pd-C in HCl)) was performed at elevated temperature (50 – 80 °C) and the obtained suspension was filtered after the hydrogenation was finished. Subsequently ethyl acetate and a solution of ammonium hydroxide were added under continuous stirring. After discontinuation of stirring, phase separation occured after which the aqueous phase was repeatedly extracted with ethyl acetate. The combined organic phases were washed with demineralized water and filtered.

[0055]  After addition of 5 – 6 N hydrogen chloride in 2-propanol and cooling precipitation of detomidine hydrochloride occured. After filtration the filtercake (i.e. raw product) was washed with ethyl acetate and dried.

[0056]  A fraction of the resulting raw product (i.e. 5 g batch RSO E-190604 RP) was recrystallized from 5 g demineralized water by heating (until complete dissolution was obtained) and subsequent cooling on an ice bath. The resulting crystals were separated by filtration and the resulting filter cake washed with 2-propanol. Subsequently, the washed product was dried under vacuum (10 mbar) at 23 °C. The obtained yield for the white crystalline substance amounted to 66.0 % of the theory.

[0057]  The resulting drug substance showed a water content (KF) of 7.49 %. The corresponding DSC curve was in line with the expectation (see for example Figure 1) and showed the two typical peaks routinely observed for DHM. Other than 2-propanol used for final washing none of the other solvents employed during the overall synthesis of this compound were found above the respective LOQ by GC-FID.

Example 2

Impurities after preparation of detomidine hydrochloride monohydrate (DHM)

[0058]  A larger batch of detomidine hydrochloride (i.e. 50 g NK E-190709-I A K1) was synthesized in line with Example 1. However, the final crystals obtained after recrystallization from 50 ml demineralized water were washed with 25 ml demineralized water instead of 2-propanol. Drying was performed at 21 °C and 10 mbar until constant weight. The obtained yield for the white crystalline substance amounted to 87.2 % of the theory which was markedly higher than the yield obtained in Example 1. The water content of this substance was determined at 7.54 % (KF) and the corresponding DSC curve showed two peaks with an onset at 95.7 °C and 159.3 °C.

[0059]  As shown below, recrystallization of the initial raw product from water (incl. washing) resulted in significant removal/reduction of impurities eluting before the detomidine peak (i.e. more polar compounds, e.g. Impurity A) as well as impurities eluting behind the detomidine peak (i.e. less polar compounds, e.g. Impurity C).

SampleRelevant compounds as detected by HPLC [area%]*
Impurity AImpurity RRT 0.84DetomidineImpurity RRT 1.75Impurity C
Raw product0.110.3399.400.040.04
Final crystallizate (K1)0.060.0699.800.010.02
*Table includes all compounds found at or above 0.04 area% in the initial raw product in the order in which they eluted from the HPLC column

[0060]  The final substance showed a very high HPLC purity of 99.80 area% (Ph. Eur. test method) and only a limited number of unknown impurities in addition to those

PATENT

https://patents.google.com/patent/WO2006108910A1/en

Example 1. Preparation of 4-[(2,3-dimethylbenzyl)]imidazole hydrochloride

(detomidine HCl)

l-Benzyl-5-(2,3-dimethylphenylhydroxymethyl)imidazole (20 kg), water (225 1), 30 % HCl (20 1), ethanol (5 1) and palladium on charcoal 10 % (4.4 kg) are charged. The mixture is stirred under 2.2 bar overpressure of hydrogen at 75 ± 5 °C for 24 hours. The reaction mixture is filtered at 45 ± 3 0C and the filter cake is washed with water (30 1). 170 1 of water is distilled off under reduced pressure and 30 % HCl (8 1) is added. The solution is cooled to 3 ± 3 0C during 2 h. The solution is seeded with crystals of detomidine HCl at 40 ± 5 °C, 30 ± 5 0C, 20 ± 5 °C and at 10 ± 5 0C, until the crystallization starts. The mixture is agitated for two hours. The crystalline compound is collected by centrifugation and washed with toluene. The crude product and water (250 1) are charged. The solution is heated to about 50 °C and stirred for 1 hour. The solution is cooled to 10 °C during 1.5 hour. The solution is filtered and 180 1 of water is distilled off under vacuum. 30 % HCl (20 1) is added and the solution is warmed to 60 0C, and then cooled to 3 ± 3 °C during 2 hours. The solution is seeded as above until the crystallization starts and agitated for two hours. The crystalline compound is collected by centrifogation and washed with toluene. The product is dried under vacuum at 39 ± 5 °C for 20 hours, at 61 ± 5 °C for 6 hours and at 85 ± 5 °C for 16 hours. The yield is 10.5 kg (78 %).

PATENT

https://patents.google.com/patent/US20080287685A1/en

  • Detomidine which is 4-[(2,3-dimethylbenzyl)]imidazole of formula I
  • is a well known pharmaceutical agent currently used as its hydrochloride salt in animal sedation.
  • [0003]The synthesis of detomidine is described in U.S. Pat. Nos. 4,443,466 and 4,584,383. The preparation of detomidine hydrochloride salt is described in U.S. Pat. No. 4,584,383, wherein detomidine obtained from the hydrogenation step is first recovered from alkaline solution as a free base after which the crystalline product is converted into its hydrochloride salt by treatment with HCl-isopropanol in ethyl acetate.
  • [0020]1-Benzyl-5-(2,3-dimethylphenylhydroxymethyl)imidazole (20 kg), water (225 l), 30% HCl (20 l), ethanol (5 l) and palladium on charcoal 10% (4.4 kg) are charged. The mixture is stirred under 2.2 bar overpressure of hydrogen at 75±5° C. for 24 hours. The reaction mixture is filtered at 45±3° C. and the filter cake is washed with water (30 l). 170 l of water is distilled off under reduced pressure and 30% HCl (8 l) is added. The solution is cooled to 3±3° C. during 2 h. The solution is seeded with crystals of detomidine HCl at 40±5° C., 30±5° C., 20±5° C. and at 10±5° C., until the crystallization starts. The mixture is agitated for two hours. The crystalline compound is collected by centrifugation and washed with toluene. The crude product and water (250 l) are charged. The solution is heated to about 50° C. and stirred for 1 hour. The solution is cooled to 10° C. during 1.5 hour. The solution is filtered and 180 l of water is distilled off under vacuum. 30% HCl (20 l) is added and the solution is warmed to 60° C., and then cooled to 3±3° C. during 2 hours. The solution is seeded as above until the crystallization starts and agitated for two hours. The crystalline compound is collected by centrifugation and washed with toluene. The product is dried under vacuum at 39±5° C. for 20 hours, at 61±5° C. for 6 hours and at 85±5° C. for 16 hours. The yield is 10.5 kg (78%).

PATENT

https://patents.google.com/patent/WO2020016827A1/en

Detomidine

Detomidine, 4-[(2,3-dimethylphenyl)methyl]-lH-Imidazole, is an a-2-andregenic agonist available under the brand name Equimidine® and Dormosedan® for use as a veterinary sedative. Detomidine is not currently approved for human use.

Detomidine and related compounds, including its 3,4 dimethyl isomer, iso-detomidine (4-(3,4- Dimethylbenzyl)-lH-imidazole) were first described in US4,443,466. Both the‘466 patent and the later US4, 584,383 describe the synthetic method of manufacturing detomidine as being based on coupling of an imidazole moiety with l-Bromo-2, 3-dimethyl benzene using a Grignard reaction. RU2448095 describes an alternative route of synthesis of the molecule based on coupling in presence of a Titanium catalyst. According to both the‘383 and‘095 patents, detomidine is purified by crystallization of its hydrochloride salt from water. The chemical structures of detomidine HC1 and iso-detomidine are shown below:

Figure imgf000002_0001

Detomidine HC1 Iso-detomidine

Two solid state forms of detomidine HC1 are known, the anhydrous and monohydrate forms.

Synthesis of the anhydrous form by crystallization of the monohydrate and further decomposition at elevated temperatures is described in US7,728,l47. Synthesis of the anhydrous form via decomposition of the monohydrate in reduced pressure is described in Laine et al (1983). According to Veldre et al (2011), the anhydrous and monohydrate forms of detomidine HC1 can easily interconvert depending on temperature and humidity.

The European Pharmacopeia 9.0 monograph (January 2014) describes detomidine HC1 for veterinary use. The monograph lists the established HPLC method for identification of detomidine and its impurities as using a Symmetry C8, 5 pm, 4.6 x 150 mm column, with a mobile phase of Ammonium phosphate buffer pH 7.9 – 65% and Acetonitrile – 35% at a flow rate of 1.0 mL/min and UV detection at 220 nm. That procedure is listed as recording three distinct impurities of detomidine:

Impurity A: (RS)-(2, 3 -dimethylphenyl)(l/f-imidazol-4-yl)m ethanol

– l/f-imidazol-5-yl)(2,3-dimethylphenyl)m ethanol

Figure imgf000003_0001

Impurity C: 4-| (2.3 -dimcthy ley clohcxyl)m ethyl |- 1 /7-im ida/olc

Figure imgf000003_0002

PCT/US18/012579 discloses topical formulations of detomidine and their uses in treating pain.

Purified detomidine for use in human pharmaceutical formulations is not known in the art.

EXAMPLE 5: Purification of organic impurities from detomidine HC1 monohvdrate

Two potential procedures for purification of organic impurities from sourced monohydrate were compared. The first attempted procedure was by direct re-crystallization of detomidine HC1 from 2.88 volumes of water, while the second included carbon treatment and precipitation of detomidine free base followed by the free base being reacted with HC1 and crystallized as monohydrate. Both procedures used the same non-GMP, off white anhydrous detomidine HC1 starting material which had previously been shown in Table 7 to contain 0.21% of iso-detomidine and 0.07% of Impurity A. All the re-crystallized materials were found to have practically the same purity level. The direct re-crystallization procedure was found to provide a product with a high yield and purity and at the same time provides a practical and scalable crystallization process which could be controlled by process parameters such as seeding and cooling rate.

Example 5 a: Direct recrvstallization

Anhydrous detomidine HC1 (4.5g) was introduced to a round-bottom flask with a magnetic stirrer and thermometer. Deionized water (l3ml) was then added and the mixture stirred and heated in a water bath. At 39°C, the complete dissolution of solids was observed, providing a clear yellow solution with a pH = 4.

The batch was gradually cooled by stirring. At 3 l°C, intensive crystallization was observed. The resulting slurry was cooled in an ice-water bath for 20 min and filtered. Flask and cake were then washed with 2 ml of cold deionized water and 3.97g of a white to cream colored solid was collected. 2.03g of the material was dried in a vacuum desiccator at ambient temperature and 20 mbar to a constant weight over 23 hrs producing a dry monohydrate – l .96g off-white crystalline solid (sample 1).

An additional l .9 lg of the material was dried in a vacuum oven at 90°C under house vacuum to a constant weight over about 24.5 hrs producing a dry anhydrate , l .68g off-white solid (sample 2)

The two samples were subjected to physical characterization and purity analysis by HPLC. The XRPD spectra and DSC and TGA thermograms of sample 1 are presented in Figures 8 -10 and of sample 2 are presented in Figures 11-13, respectively.

As shown in Table 11, direct re-crystallization resulted in the effective purification from all organic impurities, but was not effective for color. The content of iso-detomidine and of Impurity A was reduced to a level below the QL, but the off white color remained after re-crystallization.

Table 11 : properties following direct recrystallization (sample 1)

Figure imgf000023_0001

1 – below the QL

2 – system peak

Example 5b(i): Carbon treatment and detomidine free base isolation

Anhydrous detomidine HC1 (70.3g) and deionized water (220ml) were introduced to a 0.5 liter jacketed glass reactor equipped with a mechanical stirrer, thermocoupler and a circulating oil bath for heating and cooling.

The mixture was heated while stirring. At 40°C, complete dissolution was observed. Active carbon (CXV type, 5.2g) was added to the clear yellow solution and the batch stirred at 45°C for 50 minutes. Following this, the batch was filtered on through paper filter on Buchner funnel, reactor and filter washed with deionized water (20ml).

The slightly yellowish clear filtrate was reintroduced to the 0.5 liter reactor, stirred and 40% NaOH solution was added at 40°C. After 10ml NaOH solution was added, a pH of 7 was reached and precipitation began. An additional 13ml of NaOH was added over 1 hour at 42 – 52°C and intensive stirring (400 – 450 rpm) performed. The mixture at the end of the addition of NaOH had a pH of 13.

The batch was stirred at 33 – 35°C overnight then cooled to l6°C over 4 hours and stirred at this temperature for an additional hour. The resultant solid was filtered on Buchner filter, reactor and cake washed with two portions of deionized water (2><200ml). The wet solid (86g) was dried in a vacuum oven at 45°C to constant weight to produce a dry product (53.2g, Yield 90.7%) – white powder, m.p.=l 18.6 – 119.2

The dry detomidine base was analyzed for purity by HPLC, the results presented in Table 12. Table 12: Properties of detomidine base (intermediate in sample 2)

Figure imgf000024_0001

1 – system peak

Example 5b(nT Monohvdrate crystallization from detomidine base

The dry detomidine free base (53.0g) from Example 5b(i) was introduced together with 37% HC1 (29.7g) and deionized water (159g) into a 0.5 liter jacketed glass reactor equipped with a mechanical stirrer, a thermocoupler and a circulating oil bath for heating and cooling. The batch was stirred and heated to 45°C, at 37°C complete dissolution of solid was observed. The clear solution had a pH of 1. The solution was cooled gradually to 37°C and seeded with detomidine HC1 monohydrate and cooled gradually to 3°C over 4 hours, and then the batch was stirred for 45 minutes at this temperature. The solid was filtered on Buchner filter, reactor and cake washed with cold deionized water (80ml). The wet solid (61.9g) was dried in vacuum oven for 16 hours at 45°C to produce a dry product (57.8g, Yield 84.3%) – white crystalline powder (sample 2)

The dry detomidine HC1 monohydrate was analyzed for water by CKF (¾0 = 7.46%) and for purity by HPLC with the results presented in Table 13. Microscopic observation for particle morphology (regular prisms) was performed and the microscopic photograph is shown in Figure

14.

Table 13 : Properties of detomidine HC1 (sample 2)

Figure imgf000025_0001

1 – system peak

Example 5c: Re-crvstallization of detomidine HC1 to monohvdrate. bench scale experiment Anhydrous detomidine HC1 (754.6g) 37% HC1 (116. Og) and deionized water (2008g) were introduced to a 3 liter glass jacketed reactor equipped with a mechanical stirrer, two baffles, a thermocoupler and a circulating oil bath for heating and cooling. The batch was stirred and heated to 52°C, at 47°C complete dissolution was observed and the clear solution was found to have a pH of 0-0.5.

The solution was cooled gradually and at 45°C seeded with detomidine HC1 monohydrate (0.5g). Crystallization initiation was observed at 43°C and the batch was then cooled to 1.5°C during 5 hours and stirred for 12 hours at this temperature. The solid was filtered on Buchner filter and conditioned on the filter with vacuum for 40 minutes. The wet product (817g) was dried in vacuum oven to constant weight. For the first 13 hours, the material was dried at 30°C and 35-27 mbar, then for an additional 7 hours at 40°C and 30-18 mbar to produce a dry product (771.2g, Yield 94.6%) – white crystalline powder (Batch“90” in Tables 8-9; sample 3)

Dry detomidine HC1 monohydrate was analyzed for water by CKF (FhO = 7.37%) and for purity by HPLC, the results presented in Table 14. The physical characterization results are shown in Table 10 above.

The material was subjected to physical characterization and microscopic observation for particle morphology (regular prisms) microscopic photograph presented in Figure 7.

Table 14: Properties of detomidine HC1 (sample 3)

Figure imgf000026_0001

1 – system peak

EXAMPLE 6: Synthesis of iso -detomidine

Scheme 1 outlines a process for the synthesis of iso-detomidine was developed to produce a solid iso-detomidine HC1 in high yield and substantially free of impurities.

Figure imgf000027_0001

Scheme 1 : Route of synthesis of iso-detomidine

Example 6a: Sandmever Reaction

3,4 dimethyl aniline (150g, 1.24M) was mixed with acetonitrile (0.6 liter) in a 5 liter flask, chilled to lO°C and water (1.2 liter) added dropwise over 5 minutes. The mixture was cooled to 5°C with ice-ethanol bath and concentrated H2SO4 (98% wt, 363g 3.71M) was added dropwise over 30 min at 5-l0°C. Sodium nitrite (NaNC ) aqueous solution (89.7g in 300 ml water, 1.30M) was then added dropwise over 30 min at 0-5°C to give a brown solution. The resulting solution of diazonium salt was stirred at 0-5°C for an additional 30 min.

In another 5 liter flask KI (225g, 1.36M) was dissolved in water (0.8 liter) during stirring and cooled. The diazonium salt solution was added dropwise to the KI solution at 7-l3°C during 35 min, the batch stirred at 7-l3°C for 1.25 hr to give a black solution. MTBE (2.0 liter) was then added to the reaction mixture and Na2SC>4 (23.4g) was introduced in small portions during 5 min.

The mixture was settled and the organic phase separated and washed with two portions of brine (2 500ml). The organic solution was concentrated under vacuum to a volume of about 250ml.

The product was purified by vacuum distillation at ca. 40Pa, BP = 52 – 60°C to give 246g of intermediate 1 as a brown oil with a product yield of 86%.

Example 6b: TRT protection reaction

lH-Imidazole-4-carbaldehyde (45.2g, 0.47M) and acetonitrile (0.8 liter) are introduced into a 2 liter flack and cooled to 8°C, then TRT-C1 (131. Og, 0.47M) was added at 8°C and TEA (57. lg, 0.56M) was added dropwise during 20 min. The reaction mixture was stirred at 8 to l8°C for 2 hrs.

The reaction mixture was poured into a stirring mixture of water (0.72 liter) and MTBE (0.72 liter) and stirred for 10 minutes. The resulting solid was isolated by filtration on Buchner funnel and dissolved with THF (3 liter). The solution was dried over Na2SC>4 and concentrated to remove most of the solvent.

MTBE (400 ml) and PE (200ml) was added to the residue, the mixture stirred at 8°C for 16 hrs. The precipitated solid was isolated by filtration on Buchner filter and dried in air for 16 hrs at room temperature. Then the filter cake is dried by azeotropic drying with 2-Me-THF (2×500 ml) to give l29g of intermediate 2 as white solid with a yield of 66.5%.

Example 6c: Grignard reaction

A 2M solution of i-PrMgCl in THF (0.275 liter, 0.55M) and THF (1.0 liter) was introduced to a 2 liter flask at l2°C. Intermediate 1 (121.8g, 0.525M) was added dropwise during 20 min. The mixture was stirred at l2-l5°C for 3 hrs.

Intermediate 2 (84.6g, 0.25M) was added in small portions without cooling during 30 min, with a temperature rise to 25°C, to give a light brown solution. The solution was stirred for 2.5hrs at l5°C and added to aqueous solution of NH4CI (117g in 0.7 liter water) during 10 min at 5°C. PE (1.6 liter) was added during 5 min and the mixture stirred for extra 25 min.

Precipitated solid filtered on Buchner funnel and then re-slurred with mixture of MTBE (400 ml), water (600 ml) and PE (200 ml). Then the solid was filtered on Buchner funnel and re-slurred with MeOH (700 ml) at 60°C for 10 min, cooled to 20°C with cold water bath and filtered again on Buchner funnel. The solid product was dried in an air oven at 45 °C for 2 hrs to give 112 g of intermediate 3 as a white solid with a yield of 89.9%.

Example 6d: Reductive dehvdroxylation and de-protection

Intermediate 3 (l07g, 0.240M) and DCM (1.10 liter) were introduced to a 2 liter flask at 1 l°C, TFA (214 ml) was added dropwise over 5 mins with a temperature rise to l4°C.

The mixture was stirred for about 5 mins and EhSiH (94.4g, 0.794M) added dropwise during 5 mins. After stirring at 25-30°C for 16 hrs the mixture was concentrated by rotary evaporation at 40°C to a residue.

The residue of evaporation was dissolved in DCM (600 ml) and washed with 1.5M aq. HC1 (0.241iter). Organic phase was separated and washed with aq. NaOH (11.5g in 200ml water), pH of aqueous phase 13. Two phases were separated and the organic phase washed with brine (200 ml) dried over Na2S04 and filtered. The resulting solution was concentrated by rotary evaporation.

The evaporation residue was dissolved in mixture of EtOAc (500 ml) and EtOH (30 ml) and then 4M HC1 solution in dioxane (40 ml) was added dropwise in 5 minutes, pH = 1 – 2 adjusted and a white solid precipitated out.

The solid product was filtered on Buchner funnel, the cake dried in air for 16 hrs to give 36g of white solid.

The solid product was re-crystallized from iPrOH / Acetone. The dry cake (36g) and iPrOH were introduced into a 1 liter flask and heated to dissolution. Acetone (360 ml) was added to the resulting colorless solution at reflux during 10 mins. The mixture was cooled to 8°C and stirred at this temperature for additional 4.5 hrs. The solid product was filtered on Buchner funnel and dried in air for 36 hrs. 29.2g of iso-detomidine as a white solid was obtained with a yield of 54.4%. The 1H-NMR spectra of iso-detomidine is shown in Figure 15. EXAMPLE 7 : Re-crvstallization of detomidine HC1 spiked with 2% iso-detomidine

Detomidine HC1 monohydrate (26. Og), iso-detomidine HC1 (0.52g) and deionized water (68.7g) were introduced to a 100 ml glass jacketed reactor equipped with a mechanical stirrer, a thermocouple and a circulating oil bath for heating and cooling. The batch was stirred and heated to 51°C, at 47°C complete dissolution was observed.

The solution was cooled gradually and at 42°C seeded with detomidine HC1 monohydrate. Crystallization initiation was observed at 39°C and then the batch was cooled to 3°C for 5 hours, filtered on Buchner filter and conditioned on the filter with vacuum. The wet product (20.7 g) was dried in vacuum oven to constant weight to produce a dry product (20.13g, Yield 75.9%) – white crystalline powder

Dry detomidine HC1 monohydrate was analyzed for PSD and morphology, the results are presented in Table 8 (Sample. No. 91). The purity of re-crystallized material was analyzed using the optimized HPLC process disclosed herein, and the results are presented in Table 15.

Table 15 : Properties of detomidine HC1 following recrystallization from iso-detomidine spiked material

Figure imgf000030_0001

a area %

b Spiked amount, calculated

References

  1. ^ Clarke, Kathy W.; Hall, Leslie W.; Trim, Cynthia M., eds. (2014). “Principles of sedation, anticholinergic agents, and principles of premedication”. Veterinary Anaesthesia. pp. 79–100. doi:10.1016/B978-0-7020-2793-2.00004-9ISBN 978-0-7020-2793-2.
  2. ^ England GC, Clarke KW (November 1996). “Alpha 2 adrenoceptor agonists in the horse–a review”. The British Veterinary Journal152 (6): 641–57. doi:10.1016/S0007-1935(96)80118-7PMID 8979422.
  3. ^ Fornai F, Blandizzi C, del Tacca M (1990). “Central alpha-2 adrenoceptors regulate central and peripheral functions”. Pharmacological Research22 (5): 541–54. doi:10.1016/S1043-6618(05)80046-5PMID 2177556.

External links

Clinical data
AHFS/Drugs.comInternational Drug Names
ATCvet codeQN05CM90 (WHO)
Legal status
Legal statusVeterinary use only
Pharmacokinetic data
Elimination half-life30 min
Identifiers
showIUPAC name
CAS Number76631-46-4 
PubChem CID56032
ChemSpider50586 
UNII7N8K34P2XH
KEGGD07795 
ChEMBLChEMBL2110829 
CompTox Dashboard (EPA)DTXSID00227457 
Chemical and physical data
FormulaC12H14N2
Molar mass186.258 g·mol−1
3D model (JSmol)Interactive image
hideSMILESCc2cccc(Cc1cnc[nH]1)c2C
hideInChIInChI=1S/C12H14N2/c1-9-4-3-5-11(10(9)2)6-12-7-13-8-14-12/h3-5,7-8H,6H2,1-2H3,(H,13,14) Key:RHDJRPPFURBGLQ-UHFFFAOYSA-N 

////////////// DETOMIDINE, UNII-7N8K34P2XH , детомидин ,ديتوميدين, 地托咪定 , Domosedan, Farmos, SEDATIVE

#DETOMIDINE, #UNII-7N8K34P2XH , #детомидин ,#ديتوميدين, #地托咪定 , #Domosedan, #Farmos, #SEDATIVE

https://patents.google.com/patent/WO2020016827A1/en

EXAMPLES

EXAMPLE 1 : Elemental analysis of impurities found in commercially available anhydrous detomidine HC1

Example la: Anhydrous detomidine HC1 was sourced from two commercial API suppliers. Properties of the commercial batches, GMP1, GMP2 and GMP3, are presented below.

Elemental impurity analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS) on four different batches of sourced anhydrate. The results of the analysis are found in Table 1.

Table 1 : Elemental impurities in anhydrous detomidine HC1

Figure imgf000014_0001

11 Elements having levels L.T. 0.5 mg/kg (Ti, As, Hg, Pb, Mo, Pt, etc) are not presented in the table

The screening of elemental impurities shows that the GMP products contained significant levels of Pd (0.9 – 5.3 mg/kg). Pd is understood to be a catalyst used in the synthesis of detomidine (e.g., in reduction/hydrogenation methods).

Example lb: Characterization of commercially sourced material

Samples of the anhydrous detomidine products described in Table 1 were analyzed for water content and characterized by microscope, XRPD and thermal analyses. The results are summarized in Table 2.

Table 2: Characterization of commercial anhydrous detomidine HC1

Figure imgf000014_0002

a Anhydrous + mono hydrate The values presented in T able 2 demonstrate that the commercial samples of detomidine HC1 labeled as anhydrous contain some amount of monohydrate and this amount varied depending on storage conditions and packaging.

EXAMPLE 2: Stability assessment of anhvdrate and monohvdrate forms of detomidine base and detomidine HC1

Pure forms of crystalline free base, and HC1 salt (both monohydrate and anhydrate) were prepared from commercially sourced anhydrous detomidine HC1 as outlined in Table 3, and characterized using XRPD and thermal analysis. The solids were crystallized from aqueous solutions and then dried under different conditions. The crystallization and drying conditions are summarized in Table 3.

Table 3: Preparation of detomidine HC1 crystalline forms

Figure imgf000015_0001

The properties of the solids crystallized according to Table 3 are described in Table 4.

Table 4: Properties of Detomidine HC1 crystalline forms

Figure imgf000015_0002
Figure imgf000016_0001

These results demonstrate that crystallization from 2.8 – 2.9 volumes of water is effective for isolation and purification of the detomidine HC1 monohydrate drug substance. Drying of the monohydrate under mild conditions (20-40 mbar and temperatures from at least ambient to about 45 °C) provided pure monohydrate without traces of the anhydrous form.

The same monohydrate dried at elevated temperature (30-40 mbar 90°C) converted completely into the anhydrous form. The vacuum dried, hermetically closed anhydrate did not absorb water from the atmosphere and did not convert into the monohydrate. After exposure to atmospheric air, however, the anhydrate absorbed water and converted to a mixture of anhydrate and

monohydrate.

Melting points (m.p.) of the intermediate detomidine free base and hydrochloride of Sample 5 measured in open capillary corresponded with the published literature and the DSC data and are presented in Table 5. In order to evaluate effect of humidity on different forms of detomidine, a hydration study was performed. Samples of detomidine free base and hydrochloride salt were subjected to DVS analysis. These observations are in accordance with the DVS results shown in Figures 5 and 6, for detomidine free base and detomidine HC1, respectively.

Table 5: Composition and properties of known solid forms of detomidine

Figure imgf000016_0003
Figure imgf000016_0002
Figure imgf000017_0001

a -literature data

The free base was found to be crystalline and insoluble in water but it reacted readily with aqueous HC1 giving soluble detomidine hydrochloride.

Crystallization from water provided effective purification of the detomidine HC1 and formation of large regular crystals. Anhydrous detomidine hydrochloride appeared as small irregular particles whereas the possibility to control particle size distribution by crystallization parameters existed for the monohydrate.

The detomidine free base was found to be non-hygroscopic, but also able to absorb more than 1% of water at relative humidity (RH) >50%. An increase of humidity from RH 70% to RH >90% did not lead to absorption of additional water to monohydrate. During the dehydration cycle, the monohydrate began to lose water at RH -10% and converted into the anhydrate at RH =0%. Anhydrate did not absorb water at RH <30% and transformed completely to into the monohydrate at RH between 30% and 50%.

Four cycles of hydration-dehydration demonstrated good reproducibility of anhydrate- monohydrate interconversion.

An anhydrous detomidine HC1 of Sample 2 was shown to absorb water to a level of cKF 7.7% which corresponds well to the theoretical amount of water in the monohydrate form (Table 5).

The hydration profile of detomidine hydrochloride showed that the monohydrate is stable in a wide range of humidity between 10% and >90% RH. At the same time, the anhydrous form is not stable in atmospheric air and absorbs water at RH = 30 – 50%.

This data demonstrates that the anhydrous form is challenging in the aspects of water content and solid form stability and that detomidine HC1 monohydrate is more suitable for pharmaceutical development.

Example 3 : Impurity analysis of commercially sourced detomidine HC1

Using the established Pharmacopeia HPLC protocol (Symmetry C8, 5 pm, 4.6 x 150 mm column, with a mobile phase of 65% Ammonium phosphate buffer pH 7.9 and 35% Acetonitrile at a flow rate of 1.0 mL/min and UV detection at 220 nm), sourced samples of detomidine HC1 were assayed for impurities. As shown in Figure 1, a previously unreported peak was identified, which partially overlapped with that of detomidine. By LC-MS/MS analysis, this impurity was shown to have the same molecular weight as detomidine.

The established Pharmacopeia HPLC protocol did not separate the detomidine from the impurity. Therefore, for further identification of the elusive impurity, new HPLC protocols for assaying detomidine HC1 were developed. One protocol (“HPLC Protocol A”) comprised using a SunFire C8 column, IOqA, 3.5 pm, 4.6 x l50mm column with an initial mobile phase of 70% Ammonium Phosphate buffer solution, pH 7.9 and 30% Acetonitrile, at a flow rate of 1.0 mL/min and UV detection at 220 nm. To remove late eluting peaks, the flush gradient shown in Table 6 was applied after each run. This HPLC protocol allowed for a resolution factor of 3.9 between detomidine and the unidentified impurity. The quantitation level (QL) for impurities and degradation products is 0.025%. The detection level (DL) for impurities and degradation products is 0.01%.

Table 6: Flush gradient for HPLC protocol

Figure imgf000018_0001

Given its molecular weight, it was hypothesized that the impurity was iso-detomidine.

A solution of 100 pg/ml detomidine HC1 and about 1 pg/mL (about 1% of the working concentration) of detomidine impurity A and iso-detomidine were prepared and assayed using the new HPLC protocol (HPLC Protocol A), disclosed hereinabove. Figure 2 is a chromatogram showing that the previously unreported peak is confirmed as being iso-detomidine.

The analysis of commercially sourced detomidine HC1 revealed a significant additional impurity. Table 7 provides levels of the various detomidine impurities in different commercial batches. In all batches, total impurities were observed at levels of > 0.1% area.

Table 7: Impurity levels (% area) in commercial batches of detomidine.

Figure imgf000018_0002
Figure imgf000019_0001

provided by commercial supplier after undergoing the reciystallization process of Example 5, provided by inventors.

Further analysis of the peak at RRT=0.38 showed that it actually consisted of 2 separate, overlapping peaks. As shown in Figure 3, LC-MS/MS analysis confirmed one of these peaks as iso-impurity A. Further analysis, as shown in Figure 4, identified the second peak as (2,3- dimcthylphcnylX 1 //-imidazol-4-yl) methanone.

EXAMPLE 4: Optimization of the crystallization method of detomidine HC1 monohvdrate from commercial batches of anhydrous detomidine HC1

Crystallization experiments on 25, 65, and 770 gram scale were performed in 100 ml, 500 ml and 3 liter jacketed glass reactors, respectively, equipped with CBT (curved blade turbine) mechanical stirrers, circulating oil bath, thermocouples, and condensers. Stirrer speed in all experiments was between 300 – 600 rpm. Variable process parameters were: amounts of HC1, solvent ratio, cooling time/rate, seeding and cake wash. The parameters and the variation ranges were chosen according to production conditions. The crystallization parameters are summarized in Table 8.

Table 8: Crystallization parameters

Figure imgf000019_0002

a Seeding with detomidine HC1 monohydrate

b Time 24 hrs

c Seeding with anhydrous detomidine HC1

d 5.5 hrs cooling and overnight stirring at 1-3° C

e Spiked with 2% iso -detomidine

The drying parameters and solid properties of batches shown in Table 8 are described in Table 9. Table 9: Drying parameters and solid properties of detomidine monohydrate crystals

Figure imgf000020_0001

microscopic observation: Rods – aspect ratio > 2; prisms – aspect ratio < 2

u)M = mono hydrate

The data presented in Tables 8 and 9 demonstrate that crystallization from water and drying under technical vacuum gives pure detomidine HC1 monohydrate without traces of the detomidine HC1 anhydrous form. Variations of HC1 excess from 0 to 0.5 mole/mole base, cooling time from 1.5 to 24 hours and drying time from 15 to 33 hours appear to have no effect on the obtained properties of the solid form. All crystallization products appeared as pure detomidine HC1 monohydrate.

The crystallization initiation method also had no effect on crystalline form. The batches seeded with anhydrous material gave the same monohydrate as batches seeded with monohydrate and batches which crystallized spontaneously.

Contact with water for 24 hrs completely converted the anhydrous form into the monohydrate, even without complete dissolution (re-slurry).

Crystallization of the monohydrate from water gave large clear crystalline particles with a mean crystal size 0.3 – 0.7 mm, with some crystals larger than 2 mm in size. The shape of the crystals was rod-like or prism-like, if the aspect ratio of the crystals was < 2 the crystals were reported in Table 8 as prisms. A ratio of HC1 to base within the range 1.0 – 1.5 mole : mole and water to solid ratio within the range 2.1 – 2.8 V/wt were found to have no significant effect on the particle size distribution (PSD). However, a ratio of HC1 to base of about 1.5 were found to increase yields of highly pure detomidine HC1 monohydrate from under 90% (60.8%-86.4%) to over 90% (9l .4%-95.9%). Seeding also appeared to have no significant effect on PSD.

The cooling rate was found to have a weak effect on PSD. There was no effect observed for cooling over a time range between 1.5 and 5.5 hrs (mean cooling rate 0.10-0.3 l°C/min).

Slurry -to-slurry recrystallization of anhydrous material resulted in a strong reduction in particle size with the d(0.5) decreasing from 300-500m to 87m. These crystals were found irregular with no signs of prism-like or rod-like habit. In contrast, the re-slurry procedure applied to a mixture of anhydrate and monohydrate (15:85) gave a mixture of rod and prism-like crystals with d(0.5)=4l5p.

Batch size was found to have no significant effect on crystal size and shape. After scaling up from a 26g batch in 100 ml reactor to 770g in a 3 liter reactor, the PSD was very similar to that of small scale batches.

Prolonged cooling resulted in a “rounded” form of crystals. This effect was observed in two experiments, as seen in the microscopic photograph in Figure 7. In the first experiment the crystallizing suspension was cooled for 8 hrs, and in the second one it was stirred at low temperature for 12 hrs (batches 83 and 90 in Tables 8 and 9).

Under the conditions described, cooling had a strong effect on the process yield. Two re-slurry experiments were performed at the same water volume ratio as most of experiments (2.80 V/wt) but these two batches were not cooled and filtered at 24°C. In these experiments the yield dropped from 86% to 60-65% (batches 84, 85 in Tables 8 and 9).

Acceptable yields were obtained in cooled batches within the solvent volume ratio range 2.1 – 2.8 V/wt with the cooling temperature between about l.5°C – 4°C

An increase of HC1 to base molar ratio from 1 to 1.5 was found to raise the yield from 86% to 95%. Cake wash reduced the yield by 2 – 3%. Re-crystallization in presence of 2% iso- detomidine reduced the yield from 84 – 85% to 76%. The purity of the samples prepared according to methods disclosed in Tables 8 and 9, determined using the optimized HPLC method, are presented in Table 10. Table 10

Figure imgf000022_0001

E