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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 GLENMARK PHARMACEUTICALS LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 29 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 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 29 year tenure till date Aug 2016, Around 30 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 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 25 Lakh plus views on dozen plus blogs, 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 13 lakh plus views on New Drug Approvals Blog in 212 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

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Pitolisant


Pitolisant skeletal.svg

Pitolisant

1-(3-(3-(4-Chlorophenyl)propoxy)propyl)piperidine

MF  C17H26ClNO
MW  295.1703

(Wakix®)Approved EU 31/3/2016, Narcolepsy

A histamine H3 receptor antagonist/inverse agonist used to treat narcolepsy.

BF-2649; BF-2.649; FUB-649, Ciproxidine, Tiprolisant

CAS 362665-56-3, 362665-57-4 (oxalate)

ChemSpider 2D Image | 1-{3-[3-(4-Chlorophenyl)propoxy]propyl}piperidine hydrochloride (1:1) | C17H27Cl2NO

 CAS 903576-44-3(Pitolisant Hydrochloride)

1-{3-[3-(4-Chlorophenyl)propoxy]propyl}piperidine hydrochloride (1:1)

Molecular Weight 332.31
Formula C17H26ClNO ● HCl

Image result for Bioprojet

Bioprojet INNOVATOR

Jean-Charles Schwartz, Jeanne-Marie Lecomte

Pitolisant (INN) or tiprolisant (USAN) is a histamine receptor inverse agonist/antagonist selective for the H3 subtype.[1] It hasstimulant and nootropic effects in animal studies,[2] and may have several medical applications, having been researched for the treatment of narcolepsy, for which it has been granted orphan drug status in the EU and US.[3][4] It is currently in clinical trials forschizophrenia and Parkinson’s disease.[4][5][6]

Pitolisant hydrochloride was approved by European Medicine Agency (EMA) on Mar 31, 2016. It was developed and marketed as Wakix® by Bioprojet in EU.

 

Image result for Wakix®

Pitolisant hydrochloride is an antagonist/inverse agonist of the histamine H3 receptor, which is indicated in adults for the treatment of narcolepsy with or without cataplexy.

Wakix® is available as tablet for oral use, containing 4.5 mg and 18 mg of Pitolisant hydrochloride. The initial dose of 9 mg (two 4.5 mg, tablets) per day, and it should be used at the lowest effective dose, depending on individual patient response and tolerance, according to an up-titration scheme, without exceeding the dose of 36 mg/day.

Pitolisant was developed by Jean-Charles Schwartz, Walter Schunack and colleagues after the former discovered H3 receptors.[7]Pitolisant was the first clinically used H3 receptor inverse agonist.

Pitolisant, also known as Tiprolisant, is a histamine receptor inverse agonist/antagonist selective for the H3 subtype. It has stimulant and nootropic effects in animal studies, and may have several medical applications, having been researched for the treatment of narcolepsy, for which it has been granted orphan drug status in the EU and US. It is currently in clinical trials for schizophrenia and Parkinson’s disease. Pitolisant was the first clinically used H3 receptor inverse agonist.

Image result for pitolisant

The European Medicines Agency (EMA) has recommended granting marketing authorization for pitolisant (Wakix, Bioprojet Pharma) for narcolepsy with or without cataplexy, the agency announced today.

Narcolepsy is a rare sleep disorder that affects the brain’s ability to regulate the normal sleep-wake cycle, leading to excessive daytime sleepiness, including the sudden urge to sleep, and disturbed night-time sleep. Some patients also experience sudden episodes of cataplexy, potentially causing dangerous falls and increasing the risks for accidents, including car accidents. Symptoms of narcolepsy can be severe and significantly reduce quality of life.

Pitolisant “will add to the available treatment options for narcolepsy. It is a first-in-class medicine that acts on histamine H3 receptors in the brain. This leads to increased histamine release in the brain, thereby enhancing wakefulness and alertness,” the EMA notes in a news release.

The EMA recommendation for approval of pitolisant is based on an evaluation of all available safety and efficacy data conducted by the Committee for Medicinal Products for Human Use (CHMP). The data include two pivotal placebo-controlled trials involving 259 patients, as well as one uncontrolled, open-label study involving 102 patients with narcolepsy and one supportive study in 105 patients.

The studies showed that pitolisant was effective in reducing excessive daytime sleepiness in patients with narcolepsy. The beneficial effect of the drug on cataplexy was demonstrated in one of the pivotal studies as well as in the supportive study.

No major safety concerns with pitolisant emerged in testing. Insomnia, headache, and nausea were among the most common adverse effects observed in the clinical trials, and the CHMP decided on measures to mitigate these risks, the EMA said. The CHMP also requested the company conduct a long-term safety study to further investigate the safety of the drug when used over long periods.

Pitolisant for narcolepsy received orphan designation from the Committee for Orphan Medicinal Products in 2007. Orphan designation provides medicine developers access to incentives, such as fee reductions for scientific advice, with the aim of encouraging the development of treatments for rare disorders.

The CHMP opinion will now be sent to the European Commission for the adoption of a decision on a European Union–wide marketing authorization. Once that has been granted, each member state will decide on price and reimbursement based on the potential role/use of this medicine in the context of its national health system.

Image result for pitolisant

Narcolepsy-cataplexy.

Narcolepsy-cataplexy, or Gelineau syndrome, is a rare but serious disorder characterized by excessive daytime sleepiness which can be an extreme hindrance to normal professional and social activities, and which is accompanied by more or less frequent attacks of cataplexy (a sudden loss of muscle tone triggered by emotions as varied as laughter or fear) and erratic episodes of REM sleep (during wakefulness and during sleep), sometimes associated with hypnagogic hallucinations. Moreover, individuals with narcolepsy have various degrees of cognitive impairment and tend to be obese (reviewed by Dauvilliers et al., Clin. Neurophysiol., 2003, 114, 2000; Baumann and Bassetti, Sleep Med. Rev., 2005, 9, 253).

The disorder is caused by the loss of a group of neurons in the brain which produce two peptides, orexins, also known as hypocretins, located in the anterior hypothalamus and projecting to the main groups of aminergic neurons which regulate wakefulness and sleep. Patients with the disorder generally have very low levels of orexins in cerebrospinal fluid. Orexin knock-out mice display many of the symptoms seen in narcoleptic subjects, confirming the role of these peptides and thereby providing an excellent animal model of the disease (Chemelli et al., Cell, 1999, 98, 437).

Several types of treatments which can improve the symptoms of narcolepsy already exist, although they do not completely relieve symptoms and, furthermore, can cause significant side effects limiting their usefulness.

For instance, amphetamines or analogues such as methylphenidate which release catecholamines are used to treated daytime sleepiness, but these agents induce a state of excessive excitation as well as cardiovascular disturbances and also carry a potential for drug addiction.

Modafinil, a drug whose mechanism of action is unclear, also improves daytime sleepiness without causing as many side effects as amphetamines. Nonetheless, its efficacy is limited and it can cause headaches and nausea, particularly at high doses. Moreover amphetamines and/or modafinil do not appear to improve some of the most disabling symptoms of the disease, particularly cataplexy attacks, cognitive deficits and weight gain. With regard to cataplexy, treatments include antidepressants and oxybate. Effectiveness of the former has not been demonstrated (Cochrane Database Syst. Rev., 2005, 20, 3), and the latter is a drug of illegal abuse and its use is restricted.

It has also been shown that histamine H3 receptor antagonists induce the activation of histaminergic neurons in the brain which release histamine, a neurotransmitter with a crucial role in maintaining wakefulness (Schwartz et al., Physiol. Rev. 1991, 71, 1).

str1

PATENT

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2006084833&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

Pharmaceutical products with histamine H3 receptor ligand properties and 0 subsequent pharmacological activities thereof are described in EP-980300. An especially important product among those disclosed is 1-[3-[3-(4- chlorophenyl)propoxy] propyl]-piperidine. This compound is disclosed as the free base and as the oxalate salt.

5 The use of 1-[3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine as the free base is limited because of its oily nature. On the contrary, 1-[3-[3-(4- chlorophenyl)propoxy]propyl]-piperidine oxalate is a crystalline substance but its low aqueous solubility (0.025 g/ml at 230C) also limits its use as a
pharmaceutical ingredient.
0
Subsequent patents EP-1100503 and EP-1428820 mention certain salts of 1- [3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine. However, the only one specifically described is the oxalate salt. The crystalline monohydrochloride salt is not described.

Example 1 : 1-[3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine

According to the method disclosed in EP-982300, Example 78, sodium 3-piperidinopropanolate (2.127 kg; 12.88 mol), 3-(4-chlorophenyl)propyl mesylate (1.121 kg; 4.51 mol) and 0.322 mol of 15-crown-5 in 4.5 kg of dry toluene were refluxed for 4 hours. The solvent was evaporated and the residue purified by column chromatography on silica gel (eluent: methylene chloride/methanol (90/10)). The obtained oil was distilled in a fractionating equipment at reduced pressure (0.3-0.7 mmHg) and with a heating jacket at 207-2100C. The head fractions and the distilled fraction at 0.001-0.010 mmHg with a jacket temperature of 180-2000C were collected. The obtained oil (1.0 kg; 3.38 mol) corresponds to 1-[3-[3-(4-chlorophenyl)propoxy] propyl]-piperidine. Yield 75%.

Example 2: 1-[3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine
monohydrochloride

Preparation

Distilled 1-[3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine (1.0 kg) and anhydrous ethyl acetate (4.5 kg) are transferred to a 10-L glass vessel fitted with a cooling bath and a gas inlet. A stream of gaseous hydrogen chloride is bubbled in the reaction mixture at 20-250C.

The pH of the solution is checked by taking a 0.5 mL sample of the reaction mixture and diluting it with 5 mL of deionized water. The final pH must be about 3-4.

The mixture is cooled to -10°C-(-12°C) and stirred at this temperature for 1 h. The precipitate is filtered by using a sintered glass filter and washed with 0.5 L of anhydrous ethyl acetate previously cooled to 0-50C. The product is dried in a vacuum oven at 5O0C for a minimum period of 12 hours. The resulting crude 1 -[3-[3-(4-chlorophenyl)propoxy]propyl]-piperidine monohydrochloride weighs 1.10 kg.

Purification

A mixture of the above-described crude, 3.98 kg of anhydrous ethyl acetate and 0.35 kg of /-propanol is heated slowly at 55-6O0C in a 10-L glass vessel fitted with a heating and cooling system. When the solution has been completed, it is filtered through a heat-isolated sintered glass filter, keeping the temperature at 55-6O0C. The solution is transferred to a 10 L glass vessel and the mass is slowly cooled to 0-50C for about 1 hour. The mixture is stirred at this temperature for 1 hour and the precipitate is filtered through a sintered glass filter. The solid is washed with a mixture of 1.6 kg of anhydrous ethyl acetate and 0.14 kg of /-propanol cooled at 0-50C. The solid is dried in a vacuum oven at 5O0C for a minimum period of 12 hours. M. p. 117-1190C. Yield 80%.
IR spectrum (KBr): bands at 1112 and 1101 (C-O Ether/ St. asym), 2936 and 2868 (Alkane CH(CH2)) / St.), 1455 (Alkane CH(CH2)) / Deform.), 2647 and 2551 (Amine Salt / St.), 1492 (Amine / St.), 802 (Aromatic / Deform.) cm“1.

SEE

Eur. J. Pharm. Sci. 2001, 13, 249–259.

US2004220225A1.

CN101155793A


CN101171009A

References

  1.  Celanire S, Wijtmans M, Talaga P, Leurs R, de Esch IJ (December 2005). “Keynote review: histamine H3 receptor antagonists reach out for the clinic”. Drug Discov. Today. 10 (23-24): 1613–27. doi:10.1016/S1359-6446(05)03625-1. PMID 16376822.
  2.  Ligneau X, Perrin D, Landais L, Camelin JC, Calmels TP, Berrebi-Bertrand I, Lecomte JM, Parmentier R, Anaclet C, Lin JS, Bertaina-Anglade V, la Rochelle CD, d’Aniello F, Rouleau A, Gbahou F, Arrang JM, Ganellin CR, Stark H, Schunack W, Schwartz JC. BF2.649 [1-{3-[3-(4-Chlorophenyl)propoxy]propyl}piperidine, hydrochloride], a nonimidazole inverse agonist/antagonist at the human histamine H3 receptor: Preclinical pharmacology. Journal of Pharmacology and Experimental Therapeutics. 2007 Jan;320(1):365-75. PMID 17005916
  3.  Lin JS, Dauvilliers Y, Arnulf I, Bastuji H, Anaclet C, Parmentier R, Kocher L, Yanagisawa M, Lehert P, Ligneau X, Perrin D, Robert P, Roux M, Lecomte JM, Schwartz JC. An inverse agonist of the histamine H(3) receptor improves wakefulness in narcolepsy: studies in orexin-/- mice and patients. Neurobiology of Disease. 2008 Apr;30(1):74-83. PMID 18295497
  4. ^ Jump up to:a b Prous Science: Molecule of the Month September 2011
  5.  Ligneau X, Landais L, Perrin D, Piriou J, Uguen M, Denis E, Robert P, Parmentier R, Anaclet C, Lin JS, Burban A, Arrang JM, Schwartz JC. Brain histamine and schizophrenia: potential therapeutic applications of H3-receptor inverse agonists studied with BF2.649. Biochemical Pharmacology. 2007 Apr 15;73(8):1215-24. PMID 17343831
  6.  Stocking EM, Letavic MA (2008). “Histamine H3 antagonists as wake-promoting and pro-cognitive agents”. Current Topics in Medicinal Chemistry. 8 (11): 988–1002. doi:10.2174/156802608784936728. PMID 18673168.
  7.  Schwartz, Jean-Charles (May 2011). “The histamine H3 receptor: from discovery to clinical trials with pitolisant”. BPJ. doi:10.1111/j.1476-5381.2011.01286.x.

REFERENCES

1: Leu-Semenescu S, Nittur N, Golmard JL, Arnulf I. Effects of pitolisant, a histamine H3 inverse agonist, in drug-resistant idiopathic and symptomatic hypersomnia: a chart review. Sleep Med. 2014 Jun;15(6):681-7. doi: 10.1016/j.sleep.2014.01.021. Epub 2014 Mar 18. PubMed PMID: 24854887.

2: Dauvilliers Y, Bassetti C, Lammers GJ, Arnulf I, Mayer G, Rodenbeck A, Lehert P, Ding CL, Lecomte JM, Schwartz JC; HARMONY I study group. Pitolisant versus placebo or modafinil in patients with narcolepsy: a double-blind, randomised trial. Lancet Neurol. 2013 Nov;12(11):1068-75. doi: 10.1016/S1474-4422(13)70225-4. Epub 2013 Oct 7. PubMed PMID: 24107292.

3: Nirogi R, Ajjala DR, Kandikere V, Pantangi HR, Jonnala MR, Bhyrapuneni G, Muddana NR, Vurimindi H. LC-MS/MS method for the determination of pitolisant: application to rat pharmacokinetic and brain penetration studies. Biomed Chromatogr. 2013 Nov;27(11):1431-7. doi: 10.1002/bmc.2939. Epub 2013 Jun 13. PubMed PMID: 23760876.

4: Kasteleijn-Nolst Trenité D, Parain D, Genton P, Masnou P, Schwartz JC, Hirsch E. Efficacy of the histamine 3 receptor (H3R) antagonist pitolisant (formerly known as tiprolisant; BF2.649) in epilepsy: dose-dependent effects in the human photosensitivity model. Epilepsy Behav. 2013 Jul;28(1):66-70. doi: 10.1016/j.yebeh.2013.03.018. Epub 2013 May 8. PubMed PMID: 23665640.

5: Uguen M, Perrin D, Belliard S, Ligneau X, Beardsley PM, Lecomte JM, Schwartz JC. Preclinical evaluation of the abuse potential of Pitolisant, a histamine H₃ receptor inverse agonist/antagonist compared with Modafinil. Br J Pharmacol. 2013 Jun;169(3):632-44. doi: 10.1111/bph.12149. PubMed PMID: 23472741; PubMed Central PMCID: PMC3682710.

6: Brabant C, Charlier Y, Tirelli E. The histamine H₃-receptor inverse agonist pitolisant improves fear memory in mice. Behav Brain Res. 2013 Apr 15;243:199-204. doi: 10.1016/j.bbr.2012.12.063. Epub 2013 Jan 14. PubMed PMID: 23327739.

7: Zhang DD, Sisignano M, Schuh CD, Sander K, Stark H, Scholich K. Overdose of the histamine H₃ inverse agonist pitolisant increases thermal pain thresholds. Inflamm Res. 2012 Nov;61(11):1283-91. doi: 10.1007/s00011-012-0528-5. Epub 2012 Jul 21. PubMed PMID: 22820944.

8: Inocente C, Arnulf I, Bastuji H, Thibault-Stoll A, Raoux A, Reimão R, Lin JS, Franco P. Pitolisant, an inverse agonist of the histamine H3 receptor: an alternative stimulant for narcolepsy-cataplexy in teenagers with refractory sleepiness. Clin Neuropharmacol. 2012 Mar-Apr;35(2):55-60. doi: 10.1097/WNF.0b013e318246879d. PubMed PMID: 22356925.

9: Schwartz JC. The histamine H3 receptor: from discovery to clinical trials with pitolisant. Br J Pharmacol. 2011 Jun;163(4):713-21. doi: 10.1111/j.1476-5381.2011.01286.x. Review. PubMed PMID: 21615387; PubMed Central PMCID: PMC3111674.

Pitolisant
Pitolisant skeletal.svg
Names
IUPAC name

1-{3-[3-(4-Chlorophenyl)propoxy]propyl}piperidine
Other names

BF2.649
Identifiers
903576-44-3 
ChEMBL ChEMBL462605 Yes
ChemSpider 8123714 Yes
Jmol 3D model Interactive image
PubChem 9948102
Properties
C17H26ClNO
Molar mass 295.846 g/mol
Pharmacology
N07XX11 (WHO)

//////////Pitolisant Hydrochloride, Wakixhistamine H3 receptor antagonist/inverse agonist, narcolepsy, orphan drug, tiprolisant

ClC1=CC=C(CCCOCCCN2CCCCC2)C=C1

ROMIDEPSIN


Skeletal formula of (1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone  Image result for ROMIDEPSIN

Romidepsin; Depsipeptide; FK228; Chromadax; FR901228; Istodax;
Molecular Formula: C24H36N4O6S2
Molecular Weight: 540.69584 g/mol

CAS 128517-07-7

(1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-di(propan-2-yl)-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone

(E)-N-(2-amino-4-fluorophenyl)-4-((3-(pyridin-3-yl)acrylamido)methyl)benzamide

Romidepsin, also known as Istodax, is an anticancer agent used in cutaneous T-cell lymphoma (CTCL) and other peripheral T-cell lymphomas (PTCLs). Romidepsin is a natural product obtained from the bacteria Chromobacterium violaceum, and works by blocking enzymes known as histone deacetylases, thus inducing apoptosis.[1] It is sometimes referred to as depsipeptide, after the class of molecules to which it belongs. Romidepsin is branded and owned by Gloucester Pharmaceuticals, now a part of Celgene.[2]

Romidepsin, a histone deacetylase inhibitor, originally developed by Fujisawa (now Astellas Pharma), causes cell cycle arrest,
differentiation, and apoptosis in various cancer cells.

In 2004, the FDA granted fast-track designation for romidepsin as monotherapy for the treatment of cutaneous T-cell lymphoma (CTCL) in patients who have relapsed following, or become refractory to, other systemic therapies. The FDA designated romidepsin as an orphan drug and it was approved in 2009 for this indication and it was commercialized in 2010. In 2007, another fast-track designation was granted for the product as monotherapy of previously treated peripheral T-cell lymphoma.

Romidepsin (FR901228) was originally discovered and isolated from the fermentation broth of Chromobacterium violaceum No. 968. It was identified through efforts in the search for novel agents which selectively reverse the morphological phenotype of Ras oncogene-transformed cells since the Ras signaling pathway plays a critical role in cancer development. Therefore, the drug could also have multiple molecular targets for its anticancer activity besides HDAC.

FR901228 is a bicyclic depsipeptide which is structurally unrelated to any known class of cyclic peptides with an unusual disulfide bond connecting a thiol and D-cysteine.

This drug is commercially produced by fermentation; however its interesting and novel structure warrants examination of its synthesis within the context of this review

Romidepsin is a histone deacetylase (HDAC) inhibitor.HDACs catalyze the removal of acetyl groups from acetylated lysine residues in histone and non-histone proteins, resulting in the modulation of gene expression.
Romidepsin is indicated for treatment of cutaneous T-cell lymphoma (CTCL) in patients who have received at least
one prior systemic therapy; treatment of peripheral T-cell lymphoma (PTCL) in patients who have received at least
one prior therapy.

Available as an injection, containing 10 mg of romidepsin and recommended dose is 14 mg/m2 administered intravenously over a 4-hour period on days 1, 8, and 15 of a 28-day cycle until disease progression or unacceptable toxicity.

Image result for ROMIDEPSIN

History

Romidepsin was first reported in the scientific literature in 1994, by a team of researchers from Fujisawa Pharmaceutical Company (now Astellas Pharma) in Tsukuba, Japan, who isolated it in a culture of Chromobacterium violaceum from a soil sample obtained inYamagata Prefecture.[3] It was found to have little to no antibacterial activity, but was potently cytotoxic against several human cancercell lines, with no effect on normal cells; studies on mice later found it to have antitumor activity in vivo as well.[3]

The first total synthesis of romidepsin was accomplished by Harvard researchers and published in 1996.[4] Its mechanism of actionwas elucidated in 1998, when researchers from Fujisawa and the University of Tokyo found it to be a histone deacetylase inhibitorwith effects similar to those of trichostatin A.[5]

Image result for ROMIDEPSIN

Clinical trials

Phase I studies of romidepsin, initially codenamed FK228 and FR901228, began in 1997.[6] Phase II and phase III trials were conducted for a variety of indications. The most significant results were found in the treatment of cutaneous T-cell lymphoma (CTCL) and other peripheral T-cell lymphomas (PTCLs).[6]

In 2004, romidepsin received Fast Track designation from the FDA for the treatment of cutaneous T-cell lymphoma, and orphan drugstatus from the FDA and the European Medicines Agency for the same indication.[6] The FDA approved romidepsin for CTCL in November 2009[7] and approved romidepsin for other peripheral T-cell lymphomas (PTCLs) in June 2011.[8]

Mechanism of action

Romidepsin acts as a prodrug with the disulfide bond undergoing reduction within the cell to release a zinc-binding thiol.[3][9][10] The thiol reversibly interacts with a zinc atom in the binding pocket of Zn-dependent histone deacetylase to block its activity. Thus it is anHDAC inhibitor. Many HDAC inhibitors are potential treatments for cancer through the ability to epigenetically restore normal expression of tumor suppressor genes, which may result in cell cycle arrest, differentiation, and apoptosis.[11]

Image result for ROMIDEPSIN

Adverse effects

The use of romidepsin is uniformly associated with adverse effects.[12] In clinical trials, the most common were nausea and vomiting,fatigue, infection, loss of appetite, and blood disorders (including anemia, thrombocytopenia, and leukopenia). It has also been associated with infections, and with metabolic disturbances (such as abnormal electrolyte levels), skin reactions, altered taste perception, and changes in cardiac electrical conduction.[12]

CLIP

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532012001200003

Image result for ROMIDEPSIN

CLIP

Romidepsin was first isolated from the fermentation broth of Chromobacterium Violaceum WB968 in a nutrient
medium. Sterilized of 1% glucose and 1% bouillon solution were incubated with Chromobacterium Violaceum WB968, followed by further incubation with 1% glucose solution, 1% bouillon solution and adekanol gave the target romidepsin after extraction, silica gel chromatography and recrystallization.[Okuhara, M.; Goto, T.; Hori, Y. et al. US4977138A, 1990.]

The synthetic route was initiated by the deprotection L-(Fmoc)Thr-L-Val-OMe 1, subsequently coupled with
N-Alloc-S-Trt-D-Cys, followed by tosylation and then elimination to produce tripeptide 3 in the yield of 63.7% over four steps. The N-Alloc deprotection of 3 and then coupling with N-Fmoc-D-Valine were proceeded to provide tetrapeptide 4, which was subsequently removed Fmoc group to afford relative tetrapeptide 5 in 83.0% yield from compound 3. Condensation of 5 with β-hydroxy mercapto acid 6 was carried out by treating with benzotriazol-1-yl-oxy-tris-(dimethylamino)-phosphonium hexafluorphosphate (BOP) to give relative amide 7, and sequential hydrolysis yielded corresponding acid, which was performed by Mitsunobu macrolactonization
to produce depsipeptide 8 in 17.5% yield over three steps. Finally, romidepsin was obtained in the presence of iodine
in 81.0% yield and the overall yield of 7.5%.

The synthesis of intermediate β-hydroxy mercapto acid 6 commenced with the commercially available methyl 3,3-dimethoxypropionate 9. Nucleophilic addition of 9 with N,O-dimethylhydroxylamine provided Weinreb amide 10, followed by addition with lithium acetylide to give propargylic ketone 12 in the yield of 50.2% over two steps. Noyori’s asymmetric hydrogenation of ketone 12 provided (E)-alkene 14, which was removed the silyl group and then substituted with paratoluensulfonyl chloride to yield tosylate 15 in 40.6% yield across three steps. The dimethyl acetal of 15 was hydrolyzed to corresponding aldehyde by using lithium tetrafluoroborate,
which was immediately oxidized to relative carboxylic acid by applying Pinnick oxidation conditions. The trityl mercaptan was introduced by tosylate displacement to provide 6 in 65.0% yield over three steps and the overall yield of 13.3%.[2]

REF Greshock, T. J.; Johns, D. M.; Noguchi, Y., et al. Org. Lett. 2008, 10 (4), 613-616.

CLIP

Romidepsin (Istodax)
Romidepsin, a histone deacetylase inhibitor, originally developed by Fujisawa (now Astellas Pharma), causes cell cycle arrest,
differentiation, and apoptosis in various cancer cells.111 In 2004, the FDA granted fast-track designation for romidepsin as monotherapy for the treatment of cutaneous T-cell lymphoma (CTCL) in patients who have relapsed following, or become refractory
to, other systemic therapies. The FDA designated romidepsin as an orphan drug and it was approved in 2009 for this indication
and it was commercialized in 2010. In 2007, another fast-track designation was granted for the product as monotherapy of
previously treated peripheral T-cell lymphoma. Romidepsin (FR901228) was originally discovered and isolated from the fermentation
broth of Chromobacterium violaceum No. 968. It was identified through efforts in the search for novel agents which
selectively reverse the morphological phenotype of Ras oncogene-transformed cells since the Ras signaling pathway plays a
critical role in cancer development. Therefore, the drug could also have multiple molecular targets for its anticancer activity besides
HDAC.112 FR901228 is a bicyclic depsipeptide which is structurally unrelated to any known class of cyclic peptides with an unusual
disulfide bond connecting a thiol and D-cysteine. This drug is commercially produced by fermentation; however its interesting
and novel structure warrants examination of its synthesis within the context of this review.113,114 The synthesis of romidepsin
described is based on the total synthesis reported by the Williams115 and Simon groups (Scheme 20).116
L-Valine methyl ester (134) was coupled to N-Fmoc-L-threonine in the presence of the BOP reagent in 95% yield. The N-Fmoc protecting group was removed with Et2NH and the corresponding free amine was coupled to N-alloc-(S-triphenylmethyl)-D-cysteine with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI) and HOBT in DMF and CH2Cl2 to yield the tripeptide 135 in good yield. The threonine residue of tripeptide 135 was then subjected to dehydrating conditions to give alkene 136 in 95% yield. The N-alloc protecting group of the dehydrated tripeptide 136 was removed with palladium and tin reagents and the corresponding free amine was subsequently coupled with N-Fmoc-D-valine to give tetrapeptide 137 in 83% yield. After removal of the N-Fmoc protecting group of compound 137 with Et2NH amine 138 was obtained in quantitative yield. The acid coupling partner 145 for
amine 138 was prepared as follows: methyl 3,3-dimethoxypropionate (139) was converted to its corresponding Weinreb amide by standard conditions and reacted with lithium acetylide 140 to give propargylic ketone 141 in 75% yield. Noyori’s asymmetric reduction of ketone 141 using ruthenium catalyst 142 gave the (R)-propargylic alcohol in 98% ee. This was followed by Red-Al reduction of the alkyne to selectively yield (E)-alkene 143 in 58% yield for the two steps. Liberation of the primary alcohol
with tetrabutylammonium fluoride (TBAF) followed by selective tosylation gave 144 in 70% yield in two steps. Hydrolysis of the dimethyl acetal of 144 with LiBF4 was followed by a Pinnick oxidation to give the corresponding carboxylic acid. The tosylate was displaced with trityl mercaptan in the presence of tert-butyl alcohol to give allylic alcohol 145 in 65% yield for the three steps.
Aminoamide 138 was then coupled to acid 145 using BOP to give peptide 146 in quantitative yield. The methyl ester of compound 146 was hydrolyzed with lithium hydroxide to provide the free carboxylic acid which underwent macrolactonization under Mitsunobu conditions in the presence of diisopropyl azodicarboxylate (DIAD) and triphenylphosine to give macrocycle 147 in 24% yield.
Finally, the disulfide linkage was formed by treating bis-tritylsulfane 147 with iodine in methanol at room temperature to give romidepsin (XIII) in 81% yield.

111 Bertino, E. M.; Otterson, G. A. Expert Opin. Invest. Drugs 2011, 20, 1151.
112. Furumai, R.; Matsuyama, A.; Kobashi, N.; Lee, K.-H.; Nishiyama, M.; Nakajima,
H.; Tanaka, A.; Komatsu, Y.; Nishino, N.; Yoshida, M.; Horinouchi, S. Cancer
Res. 2002, 62, 4916.
113. Verdine, G. L.; Vrolijk, N. H.; Bertel, S. WO 2008083288 A2, 2008.
114. Verdine, G. L.; Vrolijk, N. H. WO 2008083290 A1, 2008.
115. Greshock, T. J.; Johns, D. M.; Noguchi, Y.; Williams, R. M. Org. Lett. 2008, 10,
613.
116. Li, K. W.; Wu, J.; Xing, W.; Simon, J. A. J. Am. Chem. Soc. 1996, 118, 7237.

CLIP

http://pubs.rsc.org/en/content/articlelanding/2009/np/b817886k#!divAbstract

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Williams’ improved synthesis of FK228.

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Williams’ synthesis of the FK228 amide isostere (74).

References

  1. Jump up^ “Romidepsin”. National Cancer Institute. Retrieved2009-09-11.
  2. Jump up^ “Romidepsin”. Gloucester Pharmaceuticals. Retrieved2009-09-11.
  3. ^ Jump up to:a b c Ueda H, Nakajima H, Hori Y, et al. (March 1994). “FR901228, a novel antitumor bicyclic depsipeptide produced byChromobacterium violaceum No. 968. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties, and antitumor activity”. Journal of Antibiotics. 47 (3): 301–10.doi:10.7164/antibiotics.47.301. PMID 7513682.
  4. Jump up^ Li KW, Wu J, Xing W, Simon JA (July 1996). “Total synthesis of the antitumor depsipeptide FR-901,228”. Journal of the American Chemical Society. 118 (30): 7237–8. doi:10.1021/ja9613724.
  5. Jump up^ Nakajima H, Kim YB, Terano H, Yoshida M, Horinouchi S (May 1998). “FR901228, a potent antitumor antibiotic, is a novel histone deacetylase inhibitor”. Experimental Cell Research. 241(1): 126–33. doi:10.1006/excr.1998.4027. PMID 9633520.
  6. ^ Jump up to:a b c Masuoka Y, Shindoh N, Inamura N (2008). “Histone deacetylase inhibitors from microorganisms: the Astellas experience”. In Petersen F, Amstutz R. Natural compounds as drugs. 2. Basel: Birkhäuser. pp. 335–59. ISBN 978-3-7643-8594-1. Retrieved on November 8, 2009 through Google Book Search.
  7. Jump up^ http://chembl.blogspot.com/2009/11/new-drug-approvals-pt-xxiii-romidepsin.html
  8. Jump up^http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm?fuseaction=Reports.MonthlyApprovalsAll
  9. Jump up^ Shigematsu, N.; Ueda, H.; Takase, S.; Tanaka, H.; Yamamoto, K.; Tada, T. (1994). “FR901228, a novel antitumor bicyclic depsipeptide produced by Chromobacterium violaceum No. 968. II. Structure determination.”. J. Antibiot. 47 (3): 311–314.doi:10.7164/antibiotics.47.311. PMID 8175483.
  10. Jump up^ Ueda, H.; Manda, T.; Matsumoto, S.; Mukumoto, S.; Nishigaki, F.; Kawamura, I.; Shimomura, K. (1994). “FR901228, a novel antitumor bicyclic depsipeptide produced by Chromobacterium violaceum No. 968. III. Antitumor activities on experimental tumors in mice.”. J. Antibiot. 47 (3): 315–323.doi:10.7164/antibiotics.47.315. PMID 8175484.
  11. Jump up^ Greshock, Thomas J.; Johns, Deidre M.; Noguchi, Yasuo; Williams, Robert M. (2008). “Improved Total Synthesis of the Potent HDAC Inhibitor FK228 (FR-901228)”. Organic Letters.10 (4): 613–616. doi:10.1021/ol702957z. PMC 3097137free to read.PMID 18205373.
  12. ^ Jump up to:a b [No authors listed] (October 2014). “ISTODEX Label Information (updated to October 2014)” (PDF). U.S. Food and Drug Administration.

External links

Romidepsin
Skeletal formula of (1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone
Romidepsin ball and spoke.png
Systematic (IUPAC) name
(1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetrazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone
Clinical data
Trade names Istodax
MedlinePlus a610005
License data
Pregnancy
category
  • US: D (Evidence of risk)
Routes of
administration
Intravenous infusion
Legal status
Legal status
Pharmacokinetic data
Bioavailability Not applicable (IV only)
Protein binding 92–94%
Metabolism Hepatic (mostly CYP3A4-mediated)
Biological half-life 3 hours
Identifiers
CAS Number 128517-07-7 
ATC code none
PubChem CID 5352062
IUPHAR/BPS 7006
UNII CX3T89XQBK 
ChEBI CHEBI:61080 
ChEMBL CHEMBL1213490 
Synonyms FK228; FR901228; Istodax
Chemical data
Formula C24H36N4O6S2
Molar mass 540.695 g/mol

//////////fast-track designation, Romidepsin, Depsipeptide,  FK228,  Chromadax,  FR901228,  Istodax, FDA 2009, Fujisawa, Astellas Pharma, 128517-07-7

CC=C1C(=O)NC(C(=O)OC2CC(=O)NC(C(=O)NC(CSSCCC=C2)C(=O)N1)C(C)C)C(C)C

Naloxegol


Image result for Naloxegol

Naloxegol

Movantik; NKTR-118; NKTR118; UNII-44T7335BKE; NKTR 118

854601-70-0  cas

1354744-91-4 (Naloxegol Oxalate)

(4R,4aS,7S,7aR,12bS)-7-[2-[2-[2-[2-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]-3-prop-2-enyl-1,2,4,5,6,7,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinoline-4a,9-diol

MF C34H53NO11
MW 651.78472 g/mol
Morphinan-3,14-diol, 4,5-epoxy-6-(3,6,9,12,15,18,21-heptaoxadocos-1-yloxy)-17-(2-propen-1-yl)-, (5α,6α)-, ethanedioate (1:1) (salt)
Naloxegol oxalate [USAN]
UNII-65I14TNM33
AZ-13337019 oxalate
Naloxegol (oxalate)
NKTR-118 oxalate;AZ-13337019 oxalate
UNII:65I14TNM33

Naloxegol oxalate (MovantikTM, Moventig)

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Naloxegol (INN; PEGylated naloxol;[1] trade names Movantik and Moventig) is a peripherallyselective opioid antagonistdeveloped by AstraZeneca, licensed from Nektar Therapeutics, for the treatment of opioid-induced constipation.[2] It was approved in 2014 in adult patients with chronic, non-cancer pain.[3] Doses of 25 mg were found safe and well tolerated for 52 weeks.[4] When given concomitantly with opioid analgesics, naloxegol reduced constipation-related side effects, while maintaining comparable levels of analgesia.[5]

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Naloxegol Oxalate was approved by the U.S. Food and Drug Administration (FDA) on Sept 16, 2014, then approved by European Medicine Agency (EMA) on Dec 8, 2014. It was developed and marketed as Movantik®(in the US)/Moventig®(in EU) by AstraZeneca.

Naloxegol oxalate is an antagonist of opioid binding at the mu-opioid receptor. It is indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain.

Movantik® is available as tablets for oral use, containing 12.5 mg or 25 mg of free Naloxegol. The recommended dose is 25 mg once daily (reduce to 12.5 mg if not tolerated).

Chemically, naloxegol is a pegylated (polyethylene glycol-modified) derivative of α-naloxol. Specifically, the 5-α-hydroxyl group of α-naloxol is connected via an ether linkage to the free hydroxyl group of a monomethoxy-terminated n=7 oligomer of PEG, shown extending at the lower left of the molecule image at right. The “n=7” defines the number of two-carbon ethylenes, and so the chain length, of the attached PEG chain, and the “monomethoxy” indicates that the terminal hydroxyl group of the PEG is “capped” with amethyl group.[6] The pegylation of the 5-α-hydroxyl side chain of naloxol prevents the drug from crossing the blood-brain barrier(BBB).[5] As such, it can be considered the antithesis of the peripherally-acting opiate loperamide which is utilized as an opiate-targeting anti-diarrheal agent that does not cause traditional opiate side-effects due to its inability to accumulate in the central nervous system in normal subjects.

Naloxegol was previously a Schedule II drug in the United States because of its chemical similarity to opium alkaloids, but was recently reclassified as a prescription drug after the FDA concluded that the impermeability of the blood-brain barrier to this compound made it non-habit-forming, and so without the potential for abuse — specifically, naloxegol was officially decontrolled on 23. January 2015. [7]

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As an opiate antagonist, it is not expected to be capable of inducing the euphoria and anxiolytic effects which are generally cited as the desirable effects of commonly abused opiates (all of which are opiate agonists) if it were to cross the BBB; it would in fact reverse the effects of opiate drugs of abuse if it entered the central nervous system.

Naloxegol is an oral polyethylene glycol (PEG) derivative of naloxone, a peripherally acting µ-opioid receptor antagonist (PAMORA) with limited potential for interfering with centrally mediated opioid analgesia. The incorporation of a polyethylene glycol moiety aims at inhibiting naloxone’s capacity to cross the blood-brain barrier, while preserving the affinity for the µ-opioid receptor [1].

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Opioid-induced bowel dysfunction (OIBD) represents a broad spectrum of symptoms that result from the actions of opioids on the CNS as well as the gastrointestinal tract. The majority of gastrointestinal effects seem to be mediated by the high number of µ-receptors that are expressed in the enteric nervous system. Naloxegol was more effective than placebo in increasing the number of spontaneous bowel movements in patients with opioid-induced constipation, including those with an inadequate response to laxatives.

Recognition of Naloxegol as a useful option in the treatment of opioid-induced constipation resulted in its approval by US-FDA for adult patients with chronic, non-cancer pain in 2014.
Naloxegol oxalate (XXI) is a peripherally acting l-opioid receptor antagonist that was approved in the USA and EU for the treatment of opioid-induced constipation in adults with chronic non-cancer pain. The drug, a pegylated version of naloxone, has significantly reduced central nervous system (CNS) penetration and works by inhibiting the binding of opioids in the gastrointestinal tract.152–154 Naloxegol oxalate was developed by Nektar and licensed to AstraZeneca. Although we were unable to find a single report in the primary or patent literature that describes the exact experimental procedures to prepare naloxegol oxalate, there havebeen reports on the preparation of closely related analogs155 with specific reports on improving the selectivity of the reduction step156 and the salt formation of the final drug substance.157 Taken together, the likely synthesis of naloxegol oxalate (XXI) is
described in Scheme 28. Naloxone (180) was treated with methoxyethyl chloride in the presence of Hunig’s base to give the protected ketone 181. Reduction of the ketone with potassium trisec-butylborohydride exclusively provided the a-alcohol 182 in 85% yield. Alternatively, sodium trialkylborohydrides could also be used to provide similar a-selective reduction in high yield.
Deprotonation of the alcohol with sodium hydride followed by alkylation with CH3(OCH2CH2)7Br (183) provided the pegylated intermediate 184 in 88% yield. Acidic removal of the methoxyethyl ether protecting group followed by treatment with oxalic acid and crystallization provided naloxegol oxalate (XXI) in good yield.

152. Corsetti, M.; Tack, J. Expert Opin. Pharmacol. 2015, 16, 399.
153. Garnock-Jones, K. P. Drugs 2015, 75, 419.
154. Leonard, J.; Baker, D. E. Ann. Pharmacother. 2015, 49, 360.
155. Bentley, M. D.; Viegas, T. X.; Goodin, R. R.; Cheng, L.; Zhao, X. US Patent
2005136031A1, 2005.
156. Cheng, L.; Bentley, M. D. WO Patent 2007124114A2, 2007.
157. Aaslund, B. L.; Aurell, C.-J.; Bohlin, M. H.; Sebhatu, T.; Ymen, B. I.; Healy, E. T.;
Jensen, D. R.; Jonaitis, D. T.; Parent, S. WO Patent 2012044243A1, 2012.
158. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm4183

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Naloxegol Synthesis

CREDIT

https://ayurajan.blogspot.in/2016/08/naloxegol.html

US20050136031A1: The patent reports detailed synthetic procedures to manufacture gram quantities of Naloxegol. The synthesis starts with Naloxone which was treated with methoxyethyl chloride in the presence of Hunig’s base to give the protected ketone. Reduction of the ketone with potassium tri-sec-butylborohydride exclusively provided the α-alcohol in 85% yield. Deprotonation of the alcohol with sodium hydride followed by alkylation with CH3(OCH2CH2)7Br  provided the pegylated Naloxone in 88% yield.

Identifications:

1H NMR (Estimated) for Naloxegol

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PATENT

US20060182692

Figure US20060182692A1-20060817-C00004

PATENT

http://www.google.co.in/patents/WO2005058367A2?cl=en

EXAMPLE 4 SYNTHESIS OF PEG 3-NALθxoL [0211] The structure of the naloxol, an exemplary small molecule drug, is shown below.

Figure imgf000059_0001

Naloxol [0212] This molecule was prepared (having a protected hydroxyl group) as part of a larger synthetic scheme as described in Example 5.

EXAMPLE 5

Figure imgf000059_0002

[0213] α,β-PEGι-naloxol was prepared. The overview of the synthesis is provided below.

Figure imgf000060_0001

(3)

Figure imgf000060_0002

(4)

5.A. Synthesis of 3-MEM-naloxone

[0214] Diisopropylethylamine (390 mg, 3.0 mmole) was added to a solution of naloxone HCl 2H2O (200 mg, 0.50 mmole) in CH2C12 (10 mL) with stining. Methoxyethyl chloride (“MEMCl,” 250 mg, 2.0 mmole) was then added dropwise to the above solution. The solution was stined at room temperature under N2 overnight.

[0215] The crude product was analyzed by HPLC, which indicated that 3-

MEM-O-naloxone (1) was formed in 97% yield. Solvents were removed by rotary evaporation to yield a sticky oil.

5.B. Synthesis of α and β epimer mixture of 3-MEM-naloxoI (2)

[0216] 3 mL of 0.2 N NaOH was added to a solution of 3-MEM-naloxone

(1) (obtained from 5.A. above, and used without further purification) in 5mL of ethanol. To this was added a solution of NaBHLt (76 mg, 2.0 mmole) in water (1 mL) dropwise. The resulting solution was stined at room temperature for 5 hours. The ethanol was removed by rotary evaporation followed by addition of a solution of 0.1 N HCl solution to destroy excess NaBKj and adjust the pH to a value of 1. The solution was washed with CHC13 to remove excess methoxyethyl chloride and its derivatives (3 x 50 mL), followed by addition of K2OO3 to raise the pH of the solution to 8.0. The product was then extracted with CHC13 (3 x 50 mL) and dried over Na2SO4. The solvent was removed by evaporation to yield a colorless sticky solid (192 mg, 0.46 mmole, 92% isolated yield based on naloxone HCl 2H2O).

[0217] HPLC indicated that the product was an α and β epimer mixture of

3-MEM-naloxol (2).

5.C. Synthesis of α and β epimer mixture of 6-CH3-OCH2CH2-O-3-MEM- naloxol (3a).

[0218] NaH (60% in mineral oil, 55 mg, 1.38 mmole) was added into a solution of 6-hydroxyl-3-MEM-naloxol (2) (192 mg, 0.46 mmole) in dimethylformamide (“DMF,” 6 mL). The mixture was stined at room temperature under N2 for 15 minutes, followed by addition of 2-bromoethyl methyl ether (320 mg, 2.30 mmole) in DMF (1 mL). The solution was then stirred at room temperature under N2 for 3 hours.

[0219] HPLC analysis revealed formation of a mixture of α- and β-6-CH3-OCH2CH2-0-3-MEM-naloxol (3) in about 88% yield. DMF was removed by a rotary evaporation to yield a sticky white solid. The product was used for subsequent transformation without further purification.

5.D. Synthesis of α and β epimer mixture of 6-CH3-OCH2CH2-naloxoI (4)

[0220] Crude α- and β-6-CH3-OCH2CH2-O-3-MEM-naloxol (3) was dissolved in 5 mL of CH2C12 to form a cloudy solution, to which was added 5 mL of trifluoroacetic acid (“TFA”). The resultant solution was stined at room temperature for 4 hours. The reaction was determined to be complete based upon HPLC assay. CH2C12 was removed by a rotary evaporator, followed by addition of 10 mL of water. To this solution was added sufficient K2OO3 to destroy excess TFA and to adjust the pH to 8. The solution was then extracted with CHC13 (3 x 50 mL), and the extracts were combined and further extracted with 0.1 N HCl solution (3 x 50 mL). The pH of the recovered water phase was adjusted to a pH of 8 by addition of K2CO3>followed by further extraction with CHC13 (3 x 50 mL). The combined organic layer was then dried with Na2SO4. The solvents were removed to yield a colorless sticky solid.

[0221] The solid was purified by passage two times through a silica gel column (2 cm x 30 cm) using CHCl3/CH3OH (30:1) as the eluent to yield a sticky solid. The purified product was determined by 1H NMR to be a mixture of α- and β epimers of 6-CH3-OCH2CH2-naloxol (4) containing ca. 30% α epimer and ca. 70% β epimer [100 mg, 0.26 mmole, 56% isolated yield based on 6-hydroxyl-3-MEM- naloxol (2)].

[0222] 1H NMR (δ, ppm, CDC13): 6.50-6.73 (2 H, multiplet, aromatic proton of naloxol), 5.78 (1 H, multiplet, olefinic proton of naloxone), 5.17 (2 H, multiplet, olefinic protons of naloxol), 4.73 (1 H, doublet, C5 proton of α naloxol), 4.57 (1 H, doublet, C5 proton of β naloxol), 3.91 (1H, multiplet, C6 proton of naloxol), 3.51-3.75 (4 H, multiplet, PEG), 3.39 (3 H, singlet, methoxy protons of PEG, α epimer), 3.36 (3 H, singlet, methoxy protons of PEG, β epimer), 3.23 (1 H, multiplet, C6 proton of β naloxol), 1.46-3.22 (14 H, multiplet, protons of naloxol).

SYN 1

PATENT

https://www.google.com/patents/WO2012044243A1?cl=en

Naloxol-polyethylene glycol conjugates are provided herein in solid phosphate and oxalate salt forms. Methods of preparing the salt forms, and pharmaceutical compositions comprising the salt forms are also provided herein. ACKGROUND

Effective pain management therapy often calls for an opioid analgesic. In addition to the desired analgesic effect, however, certain undesirable side effects, such as bowel dysfunction, nausea, constipation, among others, can accompany the use of an opioid analgesic. Such side effects may be due to opioid receptors being present outside of the central nervous system, principally in the gastrointestinal tract. Clinical and preclinical studies support the use of mPEG7-0-naloxol, a conjugate of the opioid antagonist naloxol and polyethylene glycol, to counteract undesirable side effects associated with use of opioid analgesics. When administered orally to a patient mPEG7-0-naloxol largely does not cross the blood brain barrier into the central nervous system, and has minimal impact on opioid- induced analgesia. See, e.g., WO 2005/058367; WO 2008/057579; Webster et al., “NKTR-118 Significantly Reverses Opioid-Induced Constipation,” Poster 39, 20th AAPM Annual Clinical Meeting (Phoenix, AZ), October 10, 2009.

To move a drug candidate such as mPEG7-O-naloxol to a viable pharmaceutical product, it is important to understand whether the drug candidate has polymorphic forms, as well as the relative stability and interconversions of these forms under conditions likely to be encountered upon large-scale production, transportation, storage and pre-usage preparation. Solid forms of a drug substance are often desired for their convenience in formulating a drug product. No solid form of mPEG7-O-naloxol drug substance has been made available to date, which is currently manufactured and isolated as an oil in a free base form. Exactly how to accomplish this is often not obvious. For example the number of pharmaceutical products that are oxalate salts is limited. The free base form of mPEG7-0-naloxol has not been observed to form a crystalline phase even when cooled to -60 °C and has been observed to exist as a glass with a transition temperature of

approximately -45 °C. Furthermore, mPEG7-0-naloxol in its free base form can undergo oxidative degradation upon exposure to air. Care can be taken in handling the free base, for example, storing it under inert gas, to avoid its degradation. However, a solid form of mPEG7-0-naloxol, preferably one that is stable when kept exposed to air, is desired

a naloxol-polyethlyene glycol conjugate oxalate salt, the salt comprising ionic species of mPEG7-0-naloxol and oxalic acid. The formulas of mPEG7-0-naloxol and oxalic acid are as follows:

Figure imgf000004_0001

In certain embodiments, the methods provided comprise dissolving mPEG7-0- naloxol free base in ethanol; adding methyl t-butyl ether to the dissolved mPEG?

O-naloxol solution; adding oxalic acid in methyl t-butyl ether to the dissolved mPEG7-0-naloxol over a period of at least 2 hours to produce a slurry; and filtering the slurry to yield the naloxol-polyethlyene glycol conjugate oxalate salt in solid form.

In certain embodiments, the methods provided comprise dissolving mPEG7-0- naloxol free base in acetonitrile; adding water to the dissolved mPEG7-0-naloxol solution; adding oxalic acid in ethyl acetate to the dissolved mPEG7-0-naloxol over a period of at least 2 hours to produce a slurry; and filtering the slurry to yield the naloxol-polyethlyene glycol conjugate oxalate salt in solid form.

In some embodiments, the solid salt form of mPEG7-0-naloxol is a crystalline form.

In certain embodiments a solid crystalline salt provided herein is substantially pure, having a purity of at least about 80%, at least about 85%, at least about 90%, at least about 92%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%.

In certain embodiments, the solid salt form of mPEG7-0-naloxol is a phosphate salt.

In other embodiments, the solid mPEG7-0-naloxol salt form is an oxalate salt. For instance, in some embodiments of solid oxalate salt forms provided herein, the solid mPEG7-0-naloxol oxalate salt form is in Form A, as described herein. As another example, in some embodiments of solid oxalate salt forms provided herein, the solid mPEG7-0-naloxol oxalate salt form is in Form B, as described herein. In yet other embodiments, an oxalate salt of mPEG7-0-naloxol in solid form prepared according to the methods described herein is provided.

In yet other embodiments, an dihydrogenphosphate salt of mPEG7-0-naloxol in solid form prepared according to the methods described herein is provided.

In certain embodiments of a solid mPEG7-0-naloxol oxalate salt Form B provided herein, the salt form exhibits a single endothermic peak on differential scanning calorimetry between room temperature and about 150 °C. The single endothermic peak can occur, for instance, between about 91 °C to about 94 °C. For example, in some embodiments the endothermic peak is at about 92 °C, about 92.5 °C, or about93 °C.

PATENT

http://www.google.co.in/patents/WO2005058367A2?cl=en

PATENT

CN101033228A

PATENT

https://www.google.com/patents/CN102174049A?cl=en

References and notes

  1.  Roland Seifert; Thomas Wieland; Raimund Mannhold; Hugo Kubinyi; Gerd Folkers (17 July 2006). G Protein-Coupled Receptors as Drug Targets: Analysis of Activation and Constitutive Activity. John Wiley & Sons. p. 227. ISBN 978-3-527-60695-5. Retrieved 14 May 2012.
  2.  “Nektar | R&D Pipeline | Products in Development | CNS/Pain | Oral Naloxegol (NKTR-118) and Oral NKTR-119”. Retrieved2012-05-14.
  3. “FDA approves MOVANTIK™ (naloxegol) Tablets C-II for the treatment of opioid-induced constipation in adult patients with chronic non-cancer pain”. 16 September 2014.
  4.  “Randomised clinical trial: the long-term safety and tolerability of naloxegol in patients with pain and opioid-induced constipation.”. Aliment Pharmacol Ther. 40: 771–9. Oct 2014.doi:10.1111/apt.12899. PMID 25112584.
  5. ^ Jump up to:a b Garnock-Jones KP (2015). “Naloxegol: a review of its use in patients with opioid-induced constipation”. Drugs. 75 (4): 419–425. doi:10.1007/s40265-015-0357-2.
  6.  Technically, the molecule that is attached via the ether link is O-methyl-heptaethylene glycol [that is, methoxyheptaethylene glycol, CH3OCH2CH2O(CH2CH2O)5CH2CH2OH], molecular weight 340.4, CAS number 4437-01-8. See Pubchem Staff (2016). “Compound Summary for CID 526555, Pubchem Compound 4437-01”. PubChem Compound Database. Bethesda, MD, USA: NCBI, U.S. NLM. Retrieved 28 January2016.
  7. ^http://www.deadiversion.usdoj.gov/fed_regs/rules/2015/fr0123_3.htm

1. WO2012044243A / US12015038524A1.

2. WO2005058367A2 / US7786133B2.

3. US20060182692A1 / US8067431B2.

4. CN101033228A.

5. Fudan Univ. J. Med. Sci. 2007, 34, 888-890.

WO2008057579A2 * Nov 7, 2007 May 15, 2008 Nektar Therapeutics Al, Corporation Dosage forms and co-administration of an opioid agonist and an opioid antagonist
WO2009137086A1 * May 7, 2009 Nov 12, 2009 Nektar Therapeutics Oral administration of peripherally-acting opioid antagonists
US20050136031 * Dec 16, 2004 Jun 23, 2005 Bentley Michael D. Chemically modified small molecules

Patents

7056500 United States
7662365 United States
 
8067431 United States
 
8617530 United States
 
9012469 United States

FDA Orange Book Patents

FDA Orange Book Patents: 1 of 6
Patent 7056500
Expiration Jun 29, 2024
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
FDA Orange Book Patents: 2 of 6
Patent 7662365
Expiration Oct 18, 2022
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
 
FDA Orange Book Patents: 3 of 6
Patent 8617530
Expiration Oct 18, 2022
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
 
FDA Orange Book Patents: 4 of 6
Patent 9012469
Expiration Apr 2, 2032
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
 
FDA Orange Book Patents: 5 of 6
Patent 7786133
Expiration Dec 19, 2027
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
 
FDA Orange Book Patents: 6 of 6
Patent 8067431
Expiration Dec 16, 2024
Applicant ASTRAZENECA PHARMS
Drug Application N204760 (Prescription Drug: MOVANTIK. Ingredients: NALOXEGOL OXALATE)
Naloxegol
Naloxegol.svg
Systematic (IUPAC) name
(5α,6α)-4,5-epoxy-6-(3,6,9,12,15,18,21-heptaoxadocos-1-yloxy)-17-(2-propen-1-yl)morphinan-3,14-diol
Clinical data
Trade names Movantik, Moventig
AHFS/Drugs.com movantik
License data
Pregnancy
category
  • US: C (Risk not ruled out)
Routes of
administration
Oral
Legal status
Legal status
Pharmacokinetic data
Protein binding ~4.2%
Metabolism Hepatic (CYP3A)
Biological half-life 6–11 h
Excretion Feces (68%), urine (16%)
Identifiers
CAS Number 854601-70-0
ATC code A06AH03 (WHO)
PubChem CID 56959087
ChemSpider 28651656
ChEBI CHEBI:82975
Synonyms NKTR-118
Chemical data
Formula C34H53NO11
Molar mass 651.785 g/mol

//////////////Naloxegol, Movantik,  NKTR-118,  NKTR118,  UNII-44T7335BKE, NKTR 118, 854601-70-0, EU 2014, FDA 2014

COCCOCCOCCOCCOCCOCCOCCO[C@H]1CC[C@]2([C@H]3Cc4ccc(c5c4[C@]2([C@H]1O5)CCN3CC=C)O)O

Opicapone


STR1

Image result for Opicapone

Opicapone

2,5-dichloro-3-(5-(3,4-dihydroxy-5-nitrophenyl)-1,2,4-oxadiazol-3-yl)-4,6-dimethylpyridine-1-oxide

BIA-9-1067; ONO-2370; BIA-91067
CAS No.923287-50-7

MF C15H10Cl2N4O6
MW: 411.9977

TRADE NAME (Ongentys®)

Approved EU 2016-06-24 BIAL PORTELA

PORTELA & CA. S.A. [PT/PT]; Av. Da Siderurgia Nacional, P-4745-457 S. Mamede do Coronado (PT)

LEARMONTH, David Alexander; (PT).
KISS, Laszlo Erno; (PT).
LEAL PALMA, Pedro Nuno; (PT).
DOS SANTOS FERREIRA, Humberto; (PT).
ARAÚJO SOARES DA SILVA, Patrício Manuel Vieira; (PT)

MOA:Catechol-O-methyl transferase (COMT) inhibitor

Indication:Parkinson’s disease (PD)

A COMT inhibitor used as adjunctive therapy for parkinson’s disease.

STR1

Opicapone was approved by European Medicine Agency (EMA) on Jun 24, 2016. It was developed and marketed as Ongentys® by Bial – Portela in EU.

Opicapone is a selective and reversible COMT inhibitor, used as adjunctive therapy for Parkinson’s disease.

Ongentys® is available as hard capsules, containing 25 mg and 50 mg of opicapone. The recommended dose is 50 mg, taken once a day at bedtime, at least one hour before or after levodopa combination medicines.

Catechol-O-methyltransferase (COMTa) catalyzes the transfer of a methyl group from S-adenosyl-l-methionine to catecholic substrates such as endogenous catechol neurotransmitters(2)and xenobiotics including (S)-2-amino-3-(3,4-dihydroxyphenyl)propanoic acid (l-Dopa), the gold standard drug for treatment of Parkinson’s disease (PD). Coadministration of a peripheral amino acid decarboxylase (AADC) inhibitor prevents breakdown of l-Dopa in the periphery by blocking enzymatic decarboxylation, and inhibition of COMT further improves its bioavailability by reducing the formation of 3-O-methyl-l-Dopa (3-OMD).

Abbreviations: COMT, catechol-O-methyltransferase; PD, Parkinson’s disease; AADC, amino acid decarboxylase; SAR, structure−activity relationship; ADMET, absorption, distribution, metabolism, excretion, toxicity; l-Dopa, (S)-2-amino-3-(3,4-dihydroxyphenyl)propanoic acid; 3-OMD, 3-O-methyl-l-Dopa.

“First-generation” COMT inhibitors such as pyrogallol, tropolone, and gallic acid are poorly selective and have poor efficacy in vivo. “Second-generation” inhibitors are exemplified by tolcapone 1, entacapone 2,(13) and nebicapone (BIA 3-202) 3 . Structure−activity (SAR) studies exploring the position of the nitro group and various side-chain substituents have been reported. Subtle differences in the mode of COMT inhibition by 1are thought to be relevant in terms of efficacy. Entacapone 2 is a short-acting,peripherally selective inhibitor which is taken concomitantly with every dose of l-Dopa. Albeit the most widely marketed COMT inhibitor, the clinical efficacy of 2 has been questioned. Tolcapone 1 is a more potent, longer acting but nonselective inhibitor of both cerebral and peripheral COMT. Unlike2, clinical use of 1 is severely restricted due to its elevated hepatotoxicity risk, postulated to occur through uncoupling of oxidative phosphorylation. Nebicapone 3 possesses a longer duration of peripheral COMT inhibition than 2 and more limited access to the brain than 1, but due to limited clinical experience, firm conclusions concerning safety have not yet been established. Undoubtedly therefore, a requirement exists for improved COMT inhibitors to address the unmet medical needs of many PD patients.
Figure

 Chemical structures of tolcapone 1, entacapone 2, and nebicapone 3.

ChemSpider 2D Image | Opicapone | C15H10Cl2N4O6

Opicapone

A preferred method of treatment of Parkinson’s disease is the administration of a combination of levodopa and a peripherally selective aromatic amino acid decarboxylase inhibitor (AADCI) together with a catechol-O-methyltransferase (COMT) inhibitor. The currently employed COMT inhibitors are tolcapone and entacapone. However, some authorities believe that each of these COMT inhibitors have residual problems relating to pharmacokinetic or pharmacodynamic properties, or to clinical efficiency or safety. Hence, not all patients get most benefit from their levodopa/AADCI/COMT inhibitor therapy.

Favoured new COMT inhibitors were disclosed in L. E. Kiss et al, J. Med. Chem., 2010, 53, 3396-3411 (D1), WO 2007/013830 (D2) and WO 2007/117165 (D3) which are believed to have particularly desirable properties so that patients can benefit from enhanced therapy.

D1, D2 and D3 also disclosed methods of preparing the new COMT inhibitors. Those processes, although effective, would benefit from an increase in yields. Other benefits which would be appropriate include those selected from reduction in number of process steps, reduction in number of unit operations, reduction of cycle-times, increased space yield, increased safety, easier to handle reagents/reactants and/or increase in purity of the COMT inhibitor, especially when manufacture of larger quantities are envisaged. A process has now been discovered that proceeds via a new intermediate which is suitable for manufacture of commercially useful quantities of a particularly apt COMT inhibitor in good yield. Additional benefits occur such as those selected from a reduced number of process steps and number of unit operations, reduced cycle-times, increased space yield, increased safety, with easier to handle reagents/reactants, improved impurity profile and/or good purity.

CLINICAL

https://clinicaltrials.gov/show/NCT01851850

SYN1

Discovery of a Long-Acting, Peripherally Selective Inhibitor of Catechol-O-methyltransferase

Laboratory of Chemistry
Laboratory of Pharmacology
Department of Research and Development, BIAL, À Avenida da Siderurgia Nacional, 4745-457 S. Mamede do Coronado, Portugal
J. Med. Chem., 2010, 53 (8), pp 3396–3411
*To whom correspondence should be addressed. E-mail: Psoares.silva@bial.com. Phone: +351-22-9866100. Fax: +351-22-9866192.
Abstract Image
Novel nitrocatechol-substituted heterocycles were designed and evaluated for their ability to inhibit catechol-O-methyltransferase (COMT). Replacement of the pyrazole core of the initial hit 4 with a 1,2,4-oxadiazole ring resulted in a series of compounds endowed with longer duration of COMT inhibition. Incorporation of a pyridine N-oxide residue at position 3 of the 1,2,4-oxadiazole ring led to analogue 37f, which was found to possess activity comparable to entacapone and lower toxicity in comparison to tolcapone. Lead structure 37f was systematically modified in order to improve selectivity and duration of COMT inhibition as well as to minimize toxicity. Oxadiazole 37d (2,5-dichloro-3-(5-(3,4-dihydroxy-5-nitrophenyl)-1,2,4-oxadiazol-3-yl)-4,6-dimethylpyridine 1-oxide (BIA 9-1067)) was identified as a long-acting, purely peripheral inhibitor, which is currently under clinical evaluation as an adjunct to l-Dopa therapy of Parkinson’s disease
2,5-Dichloro-3-(5-(3,4-dihydroxy-5-nitrophenyl)-1,2,4-oxadiazol-3-yl)-4,6-dimethylpyridine 1-oxide (37d). Compound 37d was synthesized by a similar procedure as described for 37a. Compound 36d (500 mg, 0.84 mmol) was reacted with BBr3 (1.05 g, 4.21 mmol) in dichloromethane (5 mL) at -78°C. Recrystallization from dichloromethane-ethanol afforded 37d (284 mg, 82%) as a yellow solid.
STR1
NMR (DMSO-d6):
1H : 11.07 (2H, br, OH), 8.11 (1H, d, J = 2 Hz, H6), 7.73 (1H, d, J = 2 Hz, H2), 2.66 (3H, s, H15),2.24 (3H, s, H14).
13C : 175.2 (C7), 164.5 (C8), 150.4 (C12), 148.7 (C3), 146.3 (C4), 139.4 (C13), 137.8 (C5), 134.1(C10), 131.1 (C11), 122.7 (C9), 116.6 (C2), 115.7 (C6), 112.7 (C1), 17.9 (C14), 16.5 (C15).
Elemental Analysis:
(C15H10Cl2N4O6) C, H, N, S: Calc: C, 43.60; H, 2.44; N, 13.56; Found: C, 44; H, 2.3; N, 13.6.

PATENT

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2007013830&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

LEARMONTH, David Alexander; (PT).
KISS, Laszlo Erno; (PT).
LEAL PALMA, Pedro Nuno; (PT).
DOS SANTOS FERREIRA, Humberto; (PT).
ARAÚJO SOARES DA SILVA, Patrício Manuel Vieira; (PT)

PATENT

The present invention in one aspect provides 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4,oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene and salts thereof, that is the compound of the formula (I):

and salts thereof.

Most aptly the compound of formula (I) is unsalted. However, salts of the hydroxy group with metal ions such as the alkali or alkaline earth metals, particularly the sodium and potassium salts are provided as well as those of highly basic organic compounds such as guanidine or the like.

Particularly suitably the compound of formula (I) or its salt is provided in a form suitable for use as a chemical intermediate. This may be, for example, in a form at least 50% pure, in crystalline form, in solid form or in an organic solvent or the like.

The compound of formula (I) is useful as an intermediate in the preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol i.e. the compound of formula II):

The compound of formula (II) may also be referred to as opicapone or 2,5-dichloro-3-(5-(3,4-dihydroxy-5-nitrophenyl)-[1,2,4]-oxadiazole-3-yl)-4,6-dimethylpyridine-1-oxide. Opicapone has been found to be more potent than tolcapone in inhibiting liver COMT both at 3 hours and 6 hours post oral administration to rats [ED50 in mg/kg, opicapone 0.87 at 3 hours and 1.12 at 6 hours as compared to tolcapone 1.28 at 3 hours and 2.08 at 6 hours]. Opicapone at a dose of 3 mg/kg was found to be more effective at inhibiting rat liver COMT with nearly complete inhibition occurring 2 to 6 hours post oral administration with only about 90% of enzyme activity recovered after 72 hours while tolcapone provided shorter duration of activity with about 84% recovery after only 9 hours. Both opicapone and tolcapone inhibit human recombinant S-COMT but opicapone has an inhibitory constant of 16pM being 10 fold lower than that for tolcapone. With respect to the desirable property of avoiding inhibition of COMT in the brain, opicapone following oral administration to the rat was found to be devoid of effect whereas tolcapone inhibited about 50% of enzyme activity over a period of 8 hours post administration.

Preparation 1

Cyanoacetamide (280g) was reacted with acetyl acetone (352.9g) in methanol (1015g) and morpholine (14.9g). The reaction was stirred under reflux at 65 °C until the reaction appeared complete. The resulting product suspension was filtered, washed with methanol and dried to provide the desired product about 97% yield.

Preparation 2

The product of Preparation 1 (159g) was suspended in acetonitrile (749.5g) and cooled to 0-5°C. Sulfuryl chloride (178.9g) was added and the reaction mixture warmed to room temperature and stirred until the reaction appeared complete.

The resulting suspension is cooled to 0-5°C and filtered. The solid was washed with acetonitrile, ethyl acetate and heptane. The product was then dried under vacuum at 50°C to yield the desired product (82%).

Preparation 3

Phosphoryl chloride (973.2g), tetramethylammonium chloride (67.3g) and compound of Preparation 2 (227.1g) were added to dichloromethane (500g). The suspension was heated to 85°C and stirred for 5 hours. Excess of phosphoryl chloride was removed by distillation in vacuo. The reaction mixture was cooled below 30°C and diluted with dichloromethane. The resulting solution was added to water (1350g) at room temperature and stirred for 30 minutes. The lower organic phase was separate and the aqueous phase extracted with dichloromethane. The organic phases were combined, washed with water and then treated with charcoal. The charcoal was filtered and a solvent swap to heptane was performed by distillation at atmospheric pressure. The solution was filtered at 50°C and then cooled to 30°C. On further cooling to 0°C

crystals were obtained. These were isolated by filtration, washed twice with heptane. After drying at 50°C the desired product was obtained typically at 88-91 % .

The above process was repeated with a reduction in dichloromethane during crystallisation and adding some methanol. The resulting plate-like crystals were more easily transferred for subsequent use.

Preparation 4a

Product of Preparation 3 (68.6g) and 1,10-phenanthroline monohydrate (0.9g) were suspended in methanol (240g) at room temperature. Water (518g) and a hydroxylamine solution (50% in water, 80.9g), were added and the mixture heated to 70-80°C and stirred for 5-6 hours. Water was added at 70-80 °C and the solution held for 1 hour to induce crystallization. Crystallization was completed by cooling to 15°C over 8 hours. The product was filtered off and washed twice with water and dried at 50°C under vacuum. The product was an off white to light yellow and the yield was 87.9% .

Preparation 4b

A suspension of 2,5-Dichloro-4,6-dimethyl-nicotinonitrile (45.0 kg) and 50% hydroxylamine (59.2 kg) in the presence of catalytic amount of 1,10-phenanthroline monohydrate (0.680 kg) in methanol / water (214 kg/362 kg) is heated to 70-80°C. The mixture is agitated at 70-80°C. Water (353 kg) is added slowly into the resulting solution while the temperature is maintained at > 79°C. The solution is cooled to 75 °C with stirring resulting in crystallization of (Z)-2,5-dichloro-N’-hydroxy-4,6-

dimethylnicotinimidamide. The suspension is further cooled to 20 °C, the solid is filtered off and the wet cake is washed with water (160 kg). (Z)-2,5-dichloro-N’-hydroxy-4,6-dimethylnicotinimidamide is dried under vacuum at max. 60°C until residual water level is max 0.15% (KF).

Example 1a

Preparation of 4-hydroxy-5-methoxy-3 nitrobenzoic acid

Vanillic acid (75g) was suspended in acetic acid (788g). The suspension was cooled to 10°C to 15°C and nitric acid (49g or 65% solution) was added over three hours at a rate which kept temperature between 10°C and 20°C. The resulting yellow orange was stirred for a further one hour at 18°C to 23°C. The suspension was filtered off, washed with acetic acid, then a mixture of acetic acid and water (1/2) and then water. Yield of 53% of a 87.9% pure product was obtained.

The above crude product was suspended in acetic acid and warmed to 105°C to 110°C until an orange brown solution is obtained. The solution was transferred to the crystallization vessel via a charcoal filter (or polish filtration) at a temperature above 85°C (optional step). The solution was then cooled to 80°C to 85°C. The mixture was stirred for one hour at 70°C to 80°C (optionally at 75°C) during which crystallization occurred. The product suspension was cooled to 20°C to 25°C for 17 hours or stirred for at least 12h at 20°C to 25 °C. The product suspension was filtered and washed with acetic acid, then acetic acid/ water (1/2) and finally water. The product was dried under vacuum at 50°C to 55°C. The yield of 70% corresponds to an overall yield of 44% for both parts of this preparation. The purity of the product assayed at 99.7% .

The preceding crystallization step is optional and the solution may be transferred to the crystallization vessel via polish filtration instead of via a charcoal filter.

The post crystallization suspension may be stirred for at least 12 hours at 20° C to 25 °C as an alternative to 17 hours.

Example 1b

Preparation of 4-hydroxy-5-methoxy-3 nitrobenzoic acid

A reactor was charged with 525 kg of glacial acetic acid and 50 kg vanillic acid. The mixture was heated with warm water gradually to 50°C in around 75 minutes. Temperature was set to 16°C. Nitric acid, 31.4 kg was then added gradually over a period of 3 hrs. When the administration was complete the mixture was allowed to stir for additional 3.5-4.5 hours.

The suspension was centrifuged whilst washed with 25 kg of acetic acid, 50 liter deionised water and 25 kg of acetic acid again. The wet crystalline material was suspended in 165 kg of acetic acid and heated at 91°C until complete dissolution. The solution was then cooled to 19.8°C and the mixture was allowed to stir for 1 hr. Centrifugation and washing with 15.2 kg acetic and 40 liter of deionised water was performed. The wet material was then dried in tray vacuum drier between 40-50°C until constant weight, for 72 hours. The dry material weight was 28.7 kg. The calculated yield was 45.4%.

Example 1c

Preparation of 4-h droxy-5-methoxy-3 nitrobenzoic acid

A suspension of vanillic acid (68.8 kg) in acetic acid (720 kg) is cooled to 17°C before an excess of a 65% nitric acid (44.0 kg) is added. After complete dosage of nitric acid the suspension is stirred for 2 hours. The suspension is filtered off and the wet cake is successively washed with acetic acid (80.0 kg), acetic acid/water (1:2 w/w – 105 kg) and finally water (80 kg – if necessary repeat). The solid is dried at 52°C for NMT 12 hours prior going to next step.

A suspension of the crude solid (650 kg) in acetic acid is warmed to 105 °C and stirred until complete dissolution of the crude solid. After polish filtration, the solution is cooled to 20°C over 3h resulting in crystallization and the suspension is stirred for 2h at 20°C. The solid is filtered off and the wet cake is successively washed with acetic acid (80 kg), acetic acid/water (1:2 w/w – 105 kg) and finally water (193 kg – if necessary repeat). 4-hydroxy-5-methoxy-3 nitrobenzoic acid pure is dried under vacuum at max. 55 °C until max 0.5% w/w residual acetic acid and max 0.2% w/w water is reached.

Example 2a

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoic acid

The process of Example la was scaled up to employ vanillic acid (375g) in acetic acid (3940g) to which was added nitric acid (65%, 245g) at 12°C over 3 hours followed by stirring for one hour. The overall yield was 40% of a 99.9% pure product.

Example 2b

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoic acid

Vanillic acid methyl ester (33g) and sodium nitrite (0.625g) are charged. Water (158mL) and 1,4-dioxane (158mL) are added at room temperature. The reaction mixture is heated to 40 °C. Nitric acid (65%) (15.75g) is added in the course of three hours and the resulting mixture is stirred for 4h after addition. The reaction mixture is sampled for completion.

The water/nitric-acid/dioxane azeotrope is distilled off in vacuum at 40 °C. The resulting product suspension is quenched by addition of sodium hydroxide solution (50% , 33.2 mL) and then stirred for 16h. The quench mixture is sampled for completion.

Then, HCl (18,5%, 70.2mL.) is added until the pH is below 1. The product is filtered off and washed with water (27.9mL). The product is then dried in vacuum at 50 °C. The overall yield was 81 % of a 97.3 % pure product.

Example 3a

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoyl chloride

A suspension of compound of Example la (1.0 eq) in dioxane (approx 4.5 vol) was treated with thionyl chloride (1.5 eq) and heated to 80°C. A clear solution formed at approximately 75 °C. The mixture was stirred for 3 hours at 80°C. Unreacted thionyl chloride was distilled off and after distillation the residue was cooled to 10°C.

Example 3 b

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoyl chloride

A suspension of compound of Example la (1.0 eq) in DCM (approx 3.4 vol) is treated with thionyl chloride (1.0 – 1.2 eq, for example 1.1 eq) and catalytic amount (0.011 eq) of DMF and the mixture is stirred for 16 h at 40°C. DCM is distilled off (approx 2.7 vol) and the residue is diluted with THF (approx 1.8 vol). The excess of thionylchloride is distilled off with THF/DCM and the residue after distillation is cooled to 10°C.

Example 3c

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoyl chloride

A suspension of compound of Example la (1.0 eq) in DCM (approx 4.5 vol) is treated with thionyl chloride (1.0 – 1.2 eq, for example 1.1 eq) and catalytic amount (0.0055 eq) of DMF and the mixture is stirred for 16 h at reflux. Unreacted thionylchloride is distilled off with DCM and the residue after distillation is diluted with THF (approx 1.8 vol) and cooled to 10°C.

The amount of DCM may be approx 3.4 as an alternative to approx 4.5 vol.

The catalytic amount of DMF may be about 0.011 eq as an alternative to 0.0055 eq.

Example 3d

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoyl chloride

In a reactor 68 kg dichloromethane, 20 kg 5-nitro- vanillic acid of example 1b, 76 gram of N,N-dimethylformamide and 13.4 kg (8 L) thionyl chloride, was charged at 20.2°C.

The mixture was heated to 40°C until all the starting material dissolved and the evolution of HCl and SO2 stopped. When all the starting material was consumed 5-10 L dichloromethane was distilled off at normal pressure at 40°C then the mixture was cooled to 20-25 °C and the distillation was continued until dry under vacuum at 40°C.

The evaporation residue was dissolved in 36 kg dry THF. The THF solution was used in

Example 4d.

Example 3e

Preparation of 4-hydroxy-5-methoxy-3-nitrobenzoyl chloride

A suspension of product of example 1C (4-hydroxy-5-methoxy-3 nitrobenzoic acid -160g, 1eq) in 1,4-dioxane (720mL, 4.5vol) is treated with thionyl chloride (169.8g, 103.7mL,1.5eq) and heated to 80°C. A clear solution is formed at approx. 75 °C. The mixture is stirred at 80 °C (3 hours). Unreacted thionyl chloride is distilled off and the residue after distillation is cooled to 10°C.

Example 4a

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

In this example the compound of formula (IV) is reacted with the compound of formula (V) to produce the compound of the formula (III).

Compound of formula (V) (1.24 eq) was suspended in 1,4-dioxane (approximately 4.5 vol) and the suspension cooled to 10°C. The acyl chloride (compound of formula (IV)) solution of Example 3a in 1,4-dioxane was added slowly maintaining the temperature below 20°C. A clear orange solution was formed. After complete addition, the reaction mixture was stirred at 20°C for one hour. Pyridine (approximately 8eq) was added and the reaction mixture heated slowly to 115°C. The mixture was stirred for 6 hours at 115°C and then cooled to 20°C.

The dioxane/pyridine was distilled off under vacuum at 70°C. The residue was kept at 80°C and ethanol (approx 8 vol) added to induce crystallization. The resulting yellow suspension was cooled to 0°C and stirred for two hours. The product was filtered off and washed with ethanol (2.5 vol) water (3.8 vol) and ethanol 2.5 vol). The product was dried under vacuum at 50 °C. Typical yields for this process are 82 to 85%.

In an optional variant, methanol was employed in place of ethanol to induce crystallization.

Example 4b

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

In a different reactor, compound of formula (V) (1.1 eq) is dissolved in DM Ac (approx 5.8 vol) and the solution is cooled to 5°C. The benzoyl chloride solution of Example 3b in THF/DCM is then added slowly maintaining the temperature below 10°C. After complete addition, the reaction mixture is stirred at 20 ±5°C. Pyridine (1.3 to 1.6 eq, for example 1.5 eq) is charged and the reaction mixture is heated slowly to 110±5°C removing low boiling components by distillation. The mixture is stirred for additional 3 h at 110±5°C.

In a further reactor, concentrated HCl (23.8 eq) is diluted with water (approx. 8.5 vol) and cooled to 10 °C. The reaction mixture in pyridine is dosed slowly to diluted hydrochloric acid. After complete addition, the resulting suspension is stirred for additional 2 h and the solid is filtered off. The crude solid is washed once with water and pre-dried on funnel.

The crude solid is suspended in DCM (approx. 28.6 vol) and the suspension is heated to 40°C to reach a clear solution. Resulting solution is cooled to 20°C and extracted with water. After phase separation, the aqueous phase is re-extracted with DCM and combined organic phase are washed once with water. DCM is distilled off under vacuum followed by addition of ethanol. Resulting suspension is further distilled to reduce the amount of DCM, then cooled to 5°C and stirred for additional 2 h. Finally, the product is filtered off, washed once with cold ethanol and dried under vacuum at 45°C.

Example 4c

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

In a second reactor, compound of formula (V) (1.1 eq) is dissolved in DMAc (approx. 7 vol) and the solution is cooled to 5°C. The benzoyl chloride solution of Example 3c in THF/DCM is added slowly maintaining the temperature below 10 °C. After complete addition, the reaction mixture is stirred at 20 ± 5°C for 30 min. Pyridine (6.9 to 7.3 eq, for example 7.14 eq) is charged and the reaction mixture is heated slowly to 110°C removing low boiling components by distillation. The mixture is stirred for additional 4 h at 110°C and cooled to 20°C.

In a third reactor an emulsion of diluted hydrochloric acid (prepared from cone. HCl (19.6 eq) and approx. 7.6 vol distilled water) and DCM (approx. 25.5 vol) is cooled to about 15 °C before the reaction mixture in pyridine is dosed slowly to the emulsion. After complete addition, the organic phase is separated and washed with water before DCM is distilled off under vacuum followed by addition of ethanol. The resulting suspension is further distilled to reduce the amount of DCM, then cooled to 5°C and stirred for additional 2 h.

Finally, the product is filtered off, washed once with cold ethanol and dried under vacuum at 45 °C.

Example 4d

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

140 kg Ν,Ν-dimethyl acetamide was charged into the reactor. 24.2 kg of amidoxime of Preparation 4 was dissolved in N,N-dimethyl acetamide while stirring at 21°C. The solution was cooled to 5-10°C. The THF solution of Example 3d was introduced slowly into the reaction mixture, 1.5-2 hrs, while the internal temperature was maintained at max. 9.5°C by external cooling. When the addition was complete the external cooling

was stopped. The internal temperature was allowed to raise to 21 °C in an hour. After stirring for 30 minutes, pyridine 53.0 kg was added to the mixture, while the temperature was in the range of 22.4°C – 20.6°C. Heating was started and the internal temperature raised to 105-115°C. The mixture started to reflux for 3h while the internal temperature managed to 113°C by partial distillation of some THF. The reaction mixture was then cooled and introduced to a mixture of 220 kg concentrated HCl and 170 kg of deionised water while the internal temperature was maintained between 14-16°C. The reactor was rinsed with 10 kg of Ν,Ν-dimethylacetamide and 20 kg deionised water. The rinse liquid was run to the mixture. The suspension was then further cooled to 5-10°C and stirred for 1.5-2.0 hours. The product was centrifuged and was washed 80 kg deionised water. Crude wet weight of the product was 88.6 kg.

The crude wet product, was dissolved in 460 kg (340 L) dichloromethane at max 40°C. When dissolved the temperature was set to 20-30°C and 120 kg deionised water was added. The organic phase was separated, the inorganic phase was extracted with 80 kg dichloromethane. The organic phase of 460 kg, was then washed with 200 kg deionised water and the phases were separated. The inorganic phase was extracted with the 80 kg dichloromethane and the organic phases were unified. The organic phase obtained so was concentrated in vacuum at 35°C to 200-240 Liter, then 260 kg ethanol 96% was continuously added and the evaporation was continued to a final 200-240 liter volume. Then the mixture was cooled to 5-10°C and was allowed to stir for 3 hrs. Centrifuging, washing with 20 kg ethanol resulted in 35.4 kg wet product. Vacuum drying for 16 hours at 45°C gave 34.09 kg dry product. The yield was 79.9%.

Example 4e

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

In a second vessel, (Z)-2,5-dichloro-N’-hydroxy-4,6-dimethylnicotiriimidamide (201.2g, 1.24eq) is suspended in 1,4-dioxane (720mL, 4.5vol) and the suspension is cooled to 10°C. The residue of example 3e in 1,4-dioxane is added slowly maintaining the temperature below 20°C. A clear orange solution is formed. After complete addition, the reaction mixture is stirred at 20°C for 1 hour. Pyridine (483.7mL, 8eq) is then charged and the reaction mixture is heated slowly to 115°C. The mixture is stirred at 115°C for 6 hours. The solution is then cooled to 20°C. Dioxane/pyridine is distilled off.

After distillation, the pit is kept at 80 °C and ethanol (1.28L, 8vol) is added at this temperature to induce crystallization. The resulting yellow suspension is cooled to 75 °C and stirred for 1h at this temperature to allow crystal growth. The product suspension is then cooled to 0 °C and stirred for 2h at this temperature. The product is filtered off and washed subsequently with ethanol (400mL, 2.5vol), water (608mL, 3.8vol) and ethanol (400mL, 2.5vol). The product is dried under vacuum at 50°C until LOD is max 1% w/w.

Example 4f

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

A mixture of compound of formula (V) (11.7g, 50 mmol, 1.25eq), methyl 4-hydroxy-3-methoxy-5-nitrobenzoate (10g, 40 mmol, leq) and a catalytic amount of p-toluenesulfonic acid (0.76g, 4mmol, 0.1eq) in dimethyl acetamide was heated to 80°C. The reaction was followed by HPLC. After 23h, 6% of conversion was obtained.

Example 4g

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-y1]-2-hydroxy-3-methoxy-1-nitrobenzene

A mixture of compound of formula (V) (11.7g, 50 mmol, 1.25eq), methyl 4-hydroxy-3-methoxy-5-nitrobenzoate (10g, 40 mmol, 1eq) and a catalytic amount of aluminum chloride (0.53g, 4mmol, 0.1eq) in dimethyl acetamide was heated to 80°C. The reaction was followed by HPLC. After 20h, 10% of conversion was obtained.

Example 5a

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

A solution of the product of Example 4a (24g) was dissolved in dichloromethane (388g) at 20-40°C. The yellow solution was cooled to 5°C and urea hydrogen-peroxide (UHP) (17.6g) and trifluoroacetic acid anhydride (37g) added and stirring continued for 12hr at 5°C. The reaction mixture was warmed to room temperature over one hour and stirring continued for a further five hours. The precipitate that formed was filtered off and washed with dichloromethane. The combined filtrates were diluted further with dichloromethane, all washed and concentrated at atmospheric pressure. Toluene was added and the resulting suspension concentrated under vacuum, to remove residual dichloromethane. Further toluene was added and the mixture checked to ensure less than 0.5% dichloromethane and less than 0.1% water was present. Formic acid was added to provide a 10-12% formic acid in toluene mixture. The resulting suspension was warmed to 90°C and stirred until complete dissolution of solid. Crude product was obtained by cooling the solution to 5-10°C until crystallization commenced. The suspension was agitated at 5-10°C until crystallization appeared complete. The solid was filtered off, washed with toluene and dried under a stream of nitrogen.

The crude product was suspended in 10-12% wt/wt solution of formic acid in toluene and warmed to 90°C until dissolution of the solid. The solution was cooled to 5°C and stirred at 5°C until crystallisation occurred. The solid was obtained by filtration and washed with toluene. This recrystallization was repeated until the product tested as containing less than 0.1 % of starting material. The pure product was dried under vacuum at 50°C.

Example 5b

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

After dissolution of the product of Example 4b (24g) in DCM (388g) at 20-40°C the yellow solution is cooled to 5°C before the temperature controlled addition of urea hydrogen peroxide complex (UHP)(17.6) and trifluoroacetic anhydride (TFAA) (37g). After addition of TFAA is complete stirring is continued for 12h at 5°C before the reaction mixture is warmed to room temperature (RT) within 1 h and stirring is continued for additional 5 h. The precipitate formed during the reaction is filtered and washed with DCM on the funnel filter. The combined filtrates are diluted with DCM (325g) and then repeatedly washed with water before concentrated at atmospheric pressure. DCM is replaced by toluene (170g) and the resulting suspension is concentrated again under vacuum to remove surplus DCM. Distillates are replaced by fresh toluene as before and the mixture is analyzed for residual water and DCM (Residual DCM after solvent switch max. 0.5%; residual water after solvent switch max. 0.1 %). Formic acid (24g) is charged resulting in an approx. 10-12 % w/w formic acid in toluene solvent mixture The resulting suspension is warmed to 90°C and stirred until compete dissolution of the solid is achieved. The crude product is crystallized by cooling of this solution to 5-10°C and subsequent agitation of the resulting suspension at 5-10°C. The solid is filtered of washed with toluene and then dried in a stream of nitrogen gas.

The crude product so obtained is suspended in an approx. 10-12 %w/w solution (176g) of formic acid in toluene. The suspension is warmed to 90°C and stirred until all product is dissolved. After cooling of this solution to 5°C and subsequent stirring at 5°C, crude product is isolated by filtration and subsequent washing of the wet product with toluene.

The re-crystallization of crude product is repeated (2 or more times). The pure product (11.8g) is dried at 50°C under vacuum.

Example 5c

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

After dissolution of the product of Example 4c (24g) in DCM (388g) at 20-40°C the yellow solution is cooled to 5°C prior to the temperature controlled addition of urea hydrogen peroxide complex (UHP) (17.6g) and trifluoroacetic acid anhydride (TFAA) (37g). After addition of TFAA is complete stirring is continued for 12h at 5°C before the reaction mixture is warmed to RT within 1 h and stirring is continued for additional 5 h. The precipitate formed during the reaction is filtered and the filter cake is washed with DCM. The combined filtrates are diluted with DCM (325g) and then repeatedly washed with water before concentrated at atmospheric pressure. DCM is replaced by toluene (170g) and the resulting suspension is concentrated again in vacuum in order to remove surplus DCM and water. Distillates are replaced by fresh toluene followed by addition of formic acid (24g). The resulting suspension is warmed to 80°C and stirring is continued in order to dissolve the solid. The product is crystallized by cooling of this solution to 5°C and subsequent agitation of the resulting suspension at 5°C. The solid is filtered, washed with toluene and then dried in a stream of nitrogen gas.

The product is suspended in a formic acid / toluene (18g/158g) mixture followed by warming of the reaction mixture to 80°C. After dissolution of the product the solution is cooled to 5°C whereby the product precipitates. After additional stirring at 5°C the suspension is filtered and the filter cake is washed with toluene.

The re-crystallization of the product is repeated. The product is used as a wet material in the next process step (12.1g product obtained if dried at max. 60°C).

Example 5d

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yI]-2-hydroxy-3-mefhoxy-1-nitrobenzene

550 kg (420 L) Dichloromethane was charged into a reactor. 34 kg of product of example 4d was added to in a short period at 20°C internal temperature. The solution was cooled to 6.5°C then 24.9 kg urea hydrogen peroxide complex (UHP) was added over a period of 20-40 minutes between 5-10°C. Stirring was continued for additional 20 minutes between 6.5-7.5°C. Trifluoroacetic anhydride, 53 kg, was administered into the reaction mixture, starting and maintaining the temperature at 6-7°C over a period of 2-3 hours. When the administration was complete the mixture was stirred for additional 30 minutes. Then the internal temperature was allowed to rise to a maximum of 25°C over a period of 1.5 hours. The internal temperature was maintained between 20-25°C and the mixture was allowed to react for additional 18-20 hrs. The reaction mixture was centrifuged and the fuge was washed with 45 kg dichloromethane. To the separated dichloromethane solution 460 kg (350 L) dichloromethane and 190 kg deionised water was added. The mixture was stirred for 10 minutes and the phases were separated for 30 minutes. The organic phase was washed again with 2×190 kg deionised water and separated as previously. Evaporation of the unified organic solution at max 35 °C under vacuum was done to a final volume of 100-120 L. Then a total of 105 kg acetonitrile was administered into the system while the distillation was continued to keep the volume at 100-120 L. When complete an additional 170 kg (220 L) acetonitrile was added to the mixture at normal pressure. This suspension was heated to 70-80°C at normal pressure while dichloromethane was distilled off continuously. The mixture was then kept stirred for an hour. The suspension was cooled to 20-25°C and was stirred for an additional 30 minutes. The suspension was then centrifuged and was washed with 30 kg acetonitrile. The wet material, 29.7 kg, was vacuum dried for 16 hrs at 30°C. Dried product yield was 81.5%.

27.7 kg product, 240 kg toluene and 29.2 kg formic acid was charged into reactor then heated to 90°C for complete dissolution for 1 hour. Then the solution was cooled to 7°C and then the suspension was kept at 7°C for additional 2 hrs. If necessary seeding was applied with 3-5 grams of pure product. The suspension was then centrifuged for 1 hour whilst washing with 28 kg cold toluene. The product was suspended in 225 kg toluene and 27.2 kg formic acid was charged. The mixture then was heated to 90°C for complete dissolution for 1 hour. Then the solution was cooled to 20-25 °C, then the suspension was kept between 15-25°C for additional 2 hrs, seeded if necessary. The suspension then was centrifuged for 60 minutes whilst washed with 28 kg cold toluene. The recrystallization process may be repeated 2-3 more times.

Drying for 24 hrs at 38-41°C under vacuum was conducted until constant weight. This resulted in 16.34 kg (58.8%) dry material.

Example 5e

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene

After dissolution of the product of Example 4e (150g) in DCM (2.43kg) at reflux, the yellow solution is cooled to 5°C prior to the temperature controlled addition of carbamide peroxide (UHP – urea hydrogen peroxide) ( 110g) and trifluoroacetic acid anhydride (TFAA) (155.1 ml in 4 portions within 2 hours). The mixture is stirred for 12h at 5°C then the reaction mixture is warmed to 25 °C over 1.5 hours and stirred for 5 hours. The precipitate formed during the reaction is filtered and the filter cake is washed with DCM (0.36 kg). The combined filtrates are warmed to 30°C and diluted with water (300g). 10% sodium hydroxide is added until pH= 4 is reached. The biphasic system is stirred for 10 minutes at 30°C and the mixture is then allowed to separate. The organic layer is then successively washed with a mixture water (750g) and 10% sodium hydroxide (7.5g) (until pH=4), 3.2% HCl solution (300g). DCM is distilled at atmospheric pressure and then replaced by toluene (1035g) applying vacuum (150mbar) and keeping internal temperature at 45°C. Formic acid (300g) and toluene (900g) are added keeping the internal temperature above 40°C. The resulting solution is distilled under vacuum (150 mbar, 45°C internal temperature) until distillation ceases. After seeding at 45°C, the slurry is stirred for 1 hour at 45°C then is cooled to 5°C over 2 hours. The suspension is stirred for at least 2 hours at 5°C and then filtered. The wet cake is washed with toluene (195g) and dried in a stream of nitrogen gas (Chemical purity of crude product min. 92 % area).

A suspension of crude product in formic acid (388g, 2wt) is warmed to 55°C and stirred until complete dissolution of the crude product. Toluene (1242g, 6.4wt) is added maintaining the internal temperature above 50 °C. The reaction is stirred at 150mBar and internal temperature 45 °C until distillation ceases. The vacuum and distillation is stopped and then seed is added at 45°C. The slurry is stirred for 1 hour at 45°C and cooled to 5°C in 2 hours. The resulting suspension is stirred for at least 2 hours at 5°C then filtered. The wet cake is washed with toluene (260g, 1.34wt). The wet cake is collected and charged into the reactor. This procedure is repeated at least twice until 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-y1]-2-hydroxy-3-methoxy-1-nitrobenzene level max is 0.1 % (a/a) prior to dry at 25°C max under vacuum.

Example 6

Example 5a was repeated on a larger scale employing product of Example 3 (82g), dichloromethane (1325g), urea peroxide (60.1g) and trifuoroacetic acid anhydride

(128g).

Example 7a

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

(Π)

Product of Example 6 (15g) was suspended in N-methyl pyrrolidone (NMP) (131.5g) and cooled to 5°C. Aluminium chloride (6.2g) and pyridine (12g) were added while maintaining the temperature at 5°C. After the addition of pyridine was complete the reaction mixture was warmed to 60 °C and maintained for 2 hours. After confirmation that less than 0.5 starting material remained, the reaction mixture was cooled, and aqueous HCl (water 233g, HCl 123g, 37%) added. The resulting yellow solid was isolated by suction filtration. The resulting wet product was washed with water and propan-2-ol (67g) and dried under vacuum.

Optionally, the crude product was suspended in ethanol (492g) and warmed to reflux. The suspension was stirred for 1 hour under reflux and then cooled to room temperature. The solid was obtained by filtration, washed with ethanol and dried under vacuum at 50°C. A typical yield of 85% was achieved.

If desired either the final ethanol crystallised material or the initially produced product after washing with propan-2-ol may be employed in preparation of micronized material for use in pharmaceutical compositions.

Example 7b

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-y1)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

An approx. 11 % w/w suspension of the product of example 5b (20g) in NMP (150g) is cooled to 5°C followed by a consecutive temperature controlled addition of aluminium chloride (8g) and pyridine (15.3g). After addition of pyridine is complete the reaction mixture is warmed to 60°C followed by additional 2 h reaction time. After complete conversion of the product of example 5b the reaction mixture is cooled before an aqueous diluted hydrochloric acid (water 293g, HCl 177g, 34%) is dosed. By addition of the hydrochloric acid, crude product precipitates from the NMP/water matrix as a yellow solid which is isolated by suction filtration. The resulting wet product is washed with water and 2-propanol in a replacement wash followed by drying of the wet crude product under vacuum.

The crude product is suspended in ethanol (282g) followed by warming of the mixture to reflux. The suspension is stirred for 1 h at reflux conditions followed by cooling to room temperature. The product is isolated by filtration of the suspension. The wet product is washed with ethanol and subsequently dried in vacuo at approx 50°C (typically weight corrected yield was 85%).

The product (20g) is suspended in formic acid (725g) before the resulting suspension is warmed to max. 67°C. Stirring is continued until complete dissolution of the product is achieved. The hot solution is filtered and the filtrate is cooled to 40 – 45°C before the product is precipitated first by concentration of the solution to approx. 40% (v/v) of its original volume followed by addition of the anti solvent 2-propanol (390g). After addition of 2-propanol is finished the resulting suspension is kept at 55-60°C for crystal ripening followed by cooling to RT and filtration. The filter cake is washed with 2-propanol followed by drying of the material at max. 58°C until loss on drying (LOD) max. 0.5% . Typically, a yield of 97-98% was obtained.

If desired the product may be employed in preparation of micronized material for use in pharmaceutical compositions.

Example 7c

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

A suspension of the product of example 5c (20g) or of example 6 (20g) in NMP (153g) is cooled to 5°C followed by a consecutive temperature controlled addition of aluminium chloride (8.2g) and pyridine (15.4g). After addition of pyridine is complete the reaction mixture is warmed to 60°C followed by additional 3 h reaction time. After complete conversion of the product of example 5c or of example 6 the crude product is

precipitated by a temperature controlled addition of an aqueous hydrochloric acid solution (water 296g, HCl 179g, 34%). Filtration of the solid followed by washing of the wet filter cake with water and 2-propanol yields a crude product wet material which is immediately dissolved in formic acid (536g). After polish filtration the filtrate is concentrated under vacuum followed by addition of the anti-solvent 2-propanol (318g). After aging of the resulting suspension at 55-60°C the suspension is cooled to RT and filtered. The wet filter cake is washed with 2-propanol. The wet product is dried under vacuum at max. 58°C until LOD max. 0.5%. The yield was in the range of 70-95%

If desired the product may be employed in preparation of micronized material for use in pharmaceutical compositions.

Example 7d

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

132 kg (147 L) N-methylpyrrolidone was charged into a 1000 L reactor. 16.3 kg of product of example 5d was then added. The suspension was cooled to 5-7°C and 6.5 kg of sublimed aluminium chloride was added in portions keeping the internal temperature between 5-10°C. The mixture was stirred for 10 minutes then 12.6 kg pyridine was added maintaining the internal temperature between 5-10°C. The mixture was warmed with water in the jacket to 20-25°C and the mixture was stirred for 30 minutes. Then the mixture is heated to 58-62 °C and reacted for around 2 hours. In a separate reactor a mixture of 240.5 kg deionised water and 146.4 kg concentrated HCl was mixed. This was cooled to 15-20°C. The reaction mixture from the demethylation was introduced into the diluted hydrochloric acid between 20-25°C. Optionally, 51.2 kg dichloromethane was added to the suspension, stirred for 30 minutes and was centrifuged, washed with 60 kg deionised water and 20 kg isopropanol. Drying gave 15.9 kg of product.

The product was suspended in 185.3 kg of ethanol. The mixture was then stirred at 78°C for an hour, then cooled to 20-25°C and stirred for 1 hour. The suspension was then centrifuged and the filtercake was washed with 44.5 kg ethanol, 96% . The solid material was dried at 50°C in vacuum in a stainless steel tray drier. 14.35 kg (90.3% yield) dry product was obtained.

A reactor was charged with 317.2 kg formic acid and dry product. The mixture was heated to 65 °C until all the solid dissolves. The hot solution was then filtered to an empty 1000 L reactor, was rinsed with 20 kg formic acid, then the formic acid solution was distilled partially off under vacuum to around 80-100L. 260 kg isopropanol was then introduced at 50-60°C and stirred for 30-35 minutes. The mixture was then cooled to 20-25°C with water in the jacket and was allowed to stir min 2 hours. The suspension was then centrifuged and was washed with 25 kg isopropanol. The wet material was removed from the fuge and was transferred into vacuum tray drier and was dried until constant weight under vacuum at 45-50°C resulting in 13.6 kg product, with a yield of 95.3% .

If desired the product may be employed in preparation of micronized material for use in pharmaceutical compositions.

Example 7e

Preparation of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

A suspension of product of Example 5e (34.1kg) in N-Methyl pyrrolidone (NMP) (182kg) is warmed to 50 °C until dissolution and then cooled to 5°C followed by a consecutive temperature controlled addition of aluminium chloride (9.8 kg) and pyridine (18.2kg). After addition of pyridine is complete the reaction mixture is warmed to 60°C and stirred for at least 2 hours. The reaction mixture is cooled to 10-16°C (e.g. 11, 13, 15°C) before an aqueous diluted hydrochloric acid (4M solution, 283L) is dosed maintaining the temperature below 25 °C. During the addition of the hydrochloric acid the crude product is precipitated from the NMP/water matrix as a yellow solid. The yellow solid is filtered and subsequently washed with water (179kg), 2-propanol (105kg). The wet solid is dried under vacuum at 55°C.

A suspension of wet product (25.1kg) in formic acid (813kg) is warmed to max. 67°C. The mixture is stirred at 67°C until complete dissolution of the product is achieved. The hot solution is filtered and the filtrate is cooled to 40 – 45°C before the product is precipitated first by concentration of the solution to approx. 40% (v/v) of its original volume followed by addition of the anti solvent 2-propanol (380kg). After addition of 2-propanol the resulting suspension is stirred at 55-60°C for crystal ripening followed by cooling to RT and filtration. The filter cake is washed with 2-propanol (38kg) and then dried at max. 58°C until LOD max. 0.5%). The product may be milled (for example using the method of Example 8).

Example 8

Micronization of 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol with MC JETMILL® type 200 milling equipment (micronization through spiral jet mills)

Equipment:

Mill: MC JETMILL® 200

Dosing unit: K-Tron T 35

Cyclone: type 600

Each micronization trial was performed on at least 2 kg of 5-(3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol.

The following working parameters have been defined for the micronization:

Feed rate range: 24.0-48.0 kg/h (200-400 g/30sec.)

Mill pressure range: 3.0-4.0 bar

Venturi pressure range: 3.0-4.0 bar; preferably the Venturi pressure is the same as the mill pressure

Using the above equipment and working parameters the microparticles of 5-(3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol comply with the following particle size specification (particle size determined by optical microscopy): D10 (EDC) is not less than 4 or 5 μm (for example not less than 5 μm), the D50 (EDC) is 10-45 or 15-30 μm (for example 15-30 μm) and the D95 (EDC) is not more than 60 or 70 μm (for example not more than 60 μm).

Example 9 (Figure 5)

2,5-Dichloro-4,6-dimethyl-nicotinonitrile is reacted with hydroxylamine in the presence of catalytic amounts of 1,10-phenanthroline monohydrate to yield the aldoxime (Z)-2,5-dichloro-N’-hydroxy-4,6-dimethylnicotinimidamide which represents the first coupling partner towards the synthesis of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene. The second coupling partner 5-nitro-vanillic acid pure is synthesized from vanillic acid by nitration with 65 % nitric acid followed by re-crystallization of the crude 5-nitro-vanillic acid intermediate from acetic acid. The convergent assembly of the oxadiazole moiety in 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene is achieved by first activation of 5-nitro-vanillic acid as its acid chloride and subsequent coupling with the aldoxime (Z)-2,5-dichloro-N’-hydroxy-4,6-dimethylnicotinimidamide. Cyclisation of the initially formed coupling product is achieved thermally to give the oxadiazole moiety by elimination of water. The reaction

mixture of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene, after ring closure reaction, is concentrated and product isolated from 1,4-dioxane/ethanol mixture in one step. Oxidation of the pyridine ring to the corresponding aryl-N-oxide (5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene) is achieved with trifluoroperoxoacetic acid which is formed in situ from UHP (Urea hydrogen peroxide complex) and trifluoroacetic acid anhydride. Unreacted 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene is subsequently removed from 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene by repeated re-crystallisation from formic acid/toluene. The analogue intermediate 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene pure with a level of 5-[3-(2,5-dichloro-4,6-dimethyl-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-2-hydroxy-3-methoxy-1-nitrobenzene below 0.10 %area is converted to 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol crude analogue by ether cleavage in the presence of a stoichiometric amount of aluminium chloride and pyridine. After completion of the reaction, the crude product is isolated by precipitation with an aqueous hydrochloric acid followed by dissolution of the precipitate in formic acid. After polish filtration of the resulting solution and partial solvent switch from formic acid to isopropanol, 5-[3-(2,5-dichloro-4,6-dimethyl-1-oxy-pyridin-3-yl)-[1,2,4]oxadiazol-5-yl]-3-nitrobenzene-1,2-diol is crystallized from the resulting formic acid/IPA crystallization matrix and finally optionally milled to the desired particle size.

PATENT

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2012107708

PATENT

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2007117165

scheme 1 depicts example how to produce a compound of the general formula IIB from a compound of the general formula IVB:

iii.

HB IVB
Scheme 1. Reagents: i. Piperidine, ethanol, reflux; ii. SO2Cl2, CCl4, reflux; iii. POCI3, 120 0C, 18 h; iv. 50% H2NOH, MeOH-H20, 1.25 mol % 1,10-phenanthroline hydrate.

The following reaction scheme 2 depicts an example how to produce certain compounds of general formula III:

I, R8 = methyl III, R8 = R9 = H
iv.
R9 = H

III, R8 = R9 = benzyl

Scheme 2. Reagents: i. 65 % HNO3, AcOH; ii. 48 % HBr (aq), 140 0C; iii. MeOH, HCl(g); iv. BnBr, K2CO3, CH3CN, reflux; v. 3N NaOH, MeOH/H2O.

The following reaction scheme 3 depicts an example how to produce the compound A, by activation of a compound according to general formula III followed by cyclisation involving condensation with a compound according to formula HB, dehydration and deprotection of the methyl residue protecting the hydroxyl group;

0C

compound A

Cited Patent Filing date Publication date Applicant Title
WO2007013830A1 Jul 26, 2006 Feb 1, 2007 Portela & Ca. S.A. Nitrocatechol derivatives as comt inhibitors
WO2007117165A1 Apr 10, 2007 Oct 18, 2007 Bial – Portela & Ca, S.A. New pharmaceutical compounds
WO2008094053A1 * Oct 10, 2007 Aug 7, 2008 Bial-Portela & Ca, S.A. Dosage regimen for comt inhibitors
WO2012107708A1 * Oct 21, 2011 Aug 16, 2012 Bial – Portela & Ca, S.A. Administration regime for nitrocatechols
US20100168113 * Apr 10, 2007 Jul 1, 2010 David Alexander Learmonth Pharmaceutical Compounds
Reference
1 * [1,2,4]-oxadiazolyl nitrocatechol derivatives“, IP.COM JOURNAL, IP.COM INC., WEST HENRIETTA, NY, US, 3 May 2012 (2012-05-03), XP013150541, ISSN: 1533-0001
2 * KISS L E ET AL: “Discovery of a long-acting, peripherally selective inhibitor of catechol-O-methyltransferase“, JOURNAL OF MEDICINAL CHEMISTRY, AMERICAN CHEMICAL SOCIETY, US, vol. 53, no. 8, 22 April 2010 (2010-04-22), pages 3396 – 3411, XP002594266, ISSN: 0022-2623, [retrieved on 20100324], DOI: 10.1021/JM1001524
3 L. E. KISS ET AL., J. MED. CHEM., vol. 53, 2010, pages 3396 – 3411
4 * RASENACK N ET AL: “MICRON-SIZE DRUG PARTICLES: COMMON AND NOVEL MICRONIZATION TECHNIQUES“, PHARMACEUTICAL DEVELOPMENT AND TECHNOLOGY, NEW YORK, NY, US, vol. 9, no. 1, 1 January 2004 (2004-01-01), pages 1 – 13, XP009055393, ISSN: 1083-7450, DOI: 10.1081/PDT-120027417

REFERENCES

1: Bicker J, Alves G, Fortuna A, Soares-da-Silva P, Falcão A. A new PAMPA model using an in-house brain lipid extract for screening the blood-brain barrier permeability of drug candidates. Int J Pharm. 2016 Jan 30. pii: S0378-5173(16)30072-2. doi: 10.1016/j.ijpharm.2016.01.074. [Epub ahead of print] PubMed PMID: 26836708.

2: Devos D, Moreau C. Opicapone for motor fluctuations in Parkinson’s disease. Lancet Neurol. 2015 Dec 22. pii: S1474-4422(15)00346-4. doi: 10.1016/S1474-4422(15)00346-4. [Epub ahead of print] PubMed PMID: 26725545.

3: Ferreira JJ, Lees A, Rocha JF, Poewe W, Rascol O, Soares-da-Silva P; Bi-Park 1 investigators. Opicapone as an adjunct to levodopa in patients with Parkinson’s disease and end-of-dose motor fluctuations: a randomised, double-blind, controlled trial. Lancet Neurol. 2015 Dec 22. pii: S1474-4422(15)00336-1. doi: 10.1016/S1474-4422(15)00336-1. [Epub ahead of print] PubMed PMID: 26725544.

4: Rascol O, Perez-Lloret S, Ferreira JJ. New treatments for levodopa-induced motor complications. Mov Disord. 2015 Sep 15;30(11):1451-60. doi: 10.1002/mds.26362. Epub 2015 Aug 21. Review. PubMed PMID: 26293004.

5: Gonçalves D, Alves G, Fortuna A, Soares-da-Silva P, Falcão A. Development of a liquid chromatography assay for the determination of opicapone and BIA 9-1079 in rat matrices. Biomed Chromatogr. 2016 Mar;30(3):312-22. doi: 10.1002/bmc.3550. Epub 2015 Aug 17. PubMed PMID: 26147707.

6: Ferreira JJ, Rocha JF, Falcão A, Santos A, Pinto R, Nunes T, Soares-da-Silva P. Effect of opicapone on levodopa pharmacokinetics, catechol-O-methyltransferase activity and motor fluctuations in patients with Parkinson’s disease. Eur J Neurol. 2015 May;22(5):815-25, e56. doi: 10.1111/ene.12666. Epub 2015 Feb 4. PubMed PMID: 25649051.

7: Bonifácio MJ, Torrão L, Loureiro AI, Palma PN, Wright LC, Soares-da-Silva P. Pharmacological profile of opicapone, a third-generation nitrocatechol catechol-O-methyl transferase inhibitor, in the rat. Br J Pharmacol. 2015 Apr;172(7):1739-52. doi: 10.1111/bph.13020. Epub 2015 Jan 20. PubMed PMID: 25409768; PubMed Central PMCID: PMC4376453.

8: Kiss LE, Soares-da-Silva P. Medicinal chemistry of catechol O-methyltransferase (COMT) inhibitors and their therapeutic utility. J Med Chem. 2014 Nov 13;57(21):8692-717. doi: 10.1021/jm500572b. Epub 2014 Sep 2. PubMed PMID: 25080080.

9: Rocha JF, Falcão A, Santos A, Pinto R, Lopes N, Nunes T, Wright LC, Vaz-da-Silva M, Soares-da-Silva P. Effect of opicapone and entacapone upon levodopa pharmacokinetics during three daily levodopa administrations. Eur J Clin Pharmacol. 2014 Sep;70(9):1059-71. doi: 10.1007/s00228-014-1701-2. Epub 2014 Jun 14. PubMed PMID: 24925090.

10: Rocha JF, Santos A, Falcão A, Lopes N, Nunes T, Pinto R, Soares-da-Silva P. Effect of moderate liver impairment on the pharmacokinetics of opicapone. Eur J Clin Pharmacol. 2014 Mar;70(3):279-86. doi: 10.1007/s00228-013-1602-9. Epub 2013 Nov 24. PubMed PMID: 24271646.

11: Bonifácio MJ, Sutcliffe JS, Torrão L, Wright LC, Soares-da-Silva P. Brain and peripheral pharmacokinetics of levodopa in the cynomolgus monkey following administration of opicapone, a third generation nitrocatechol COMT inhibitor. Neuropharmacology. 2014 Feb;77:334-41. doi: 10.1016/j.neuropharm.2013.10.014. Epub 2013 Oct 19. PubMed PMID: 24148813.

12: Gonçalves D, Alves G, Fortuna A, Soares-da-Silva P, Falcão A. An HPLC-DAD method for the simultaneous quantification of opicapone (BIA 9-1067) and its active metabolite in human plasma. Analyst. 2013 Apr 21;138(8):2463-9. doi: 10.1039/c3an36671e. PubMed PMID: 23476919.

13: Rocha JF, Almeida L, Falcão A, Palma PN, Loureiro AI, Pinto R, Bonifácio MJ, Wright LC, Nunes T, Soares-da-Silva P. Opicapone: a short lived and very long acting novel catechol-O-methyltransferase inhibitor following multiple dose administration in healthy subjects. Br J Clin Pharmacol. 2013 Nov;76(5):763-75. doi: 10.1111/bcp.12081. PubMed PMID: 23336248; PubMed Central PMCID: PMC3853535.

14: Almeida L, Rocha JF, Falcão A, Palma PN, Loureiro AI, Pinto R, Bonifácio MJ, Wright LC, Nunes T, Soares-da-Silva P. Pharmacokinetics, pharmacodynamics and tolerability of opicapone, a novel catechol-O-methyltransferase inhibitor, in healthy subjects: prediction of slow enzyme-inhibitor complex dissociation of a short-living and very long-acting inhibitor. Clin Pharmacokinet. 2013 Feb;52(2):139-51. doi: 10.1007/s40262-012-0024-7. PubMed PMID: 23248072.

15: Palma PN, Bonifácio MJ, Loureiro AI, Soares-da-Silva P. Computation of the binding affinities of catechol-O-methyltransferase inhibitors: multisubstate relative free energy calculations. J Comput Chem. 2012 Apr 5;33(9):970-86. doi: 10.1002/jcc.22926. Epub 2012 Jan 25. PubMed PMID: 22278964.

16: Gonçalves D, Alves G, Soares-da-Silva P, Falcão A. Bioanalytical chromatographic methods for the determination of catechol-O-methyltransferase inhibitors in rodents and human samples: a review. Anal Chim Acta. 2012 Jan 13;710:17-32. doi: 10.1016/j.aca.2011.10.026. Epub 2011 Oct 20. Review. PubMed PMID: 22123108.

17: Kiss LE, Ferreira HS, Torrão L, Bonifácio MJ, Palma PN, Soares-da-Silva P, Learmonth DA. Discovery of a long-acting, peripherally selective inhibitor of catechol-O-methyltransferase. J Med Chem. 2010 Apr 22;53(8):3396-411. doi: 10.1021/jm1001524. PubMed PMID: 20334432.

////////BIA-9-1067,  ONO-2370,  BIA-91067, 923287-50-7, Opicapone, Catechol-O-methyl transferase, COMT inhibitor, Parkinson’s disease, PD, BIA 9-1067,  BIA 91067,  BIA-91067,  BIA91067, EU 2016

OC1=CC(C2=NC(C3=C(Cl)[N+]([O-])=C(C)C(Cl)=C3C)=NO2)=CC([N+]([O-])=O)=C1O

RPL 554


STR1

RPL554.png

ChemSpider 2D Image | RPL-554 | C26H31N5O4

UNII-3E3D8T1GIX.png

RPL-554

  • Molecular FormulaC26H31N5O4
  • Average mass477.555
RPL 554
Urea, N-[2-[(2E)-6,7-dihydro-9,10-dimethoxy-4-oxo-2-[(2,4,6-trimethylphenyl)imino]-2H-pyrimido[6,1-a]isoquinolin-3(4H)-yl]ethyl]-
(2-[(2E)-9,10-DIMETHOXY-4-OXO-2-[(2,4,6-TRIMETHYLPHENYL)IMINO]-2H,3H,4H,6H,7H-PYRIMIDO[4,3-A]ISOQUINOLIN-3-YL]ETHYL)UREA
2-[9,10-dimethoxy-4-oxo-2-(2,4,6-trimethylphenyl)imino-6,7-dihydropyrimido[6,1-a]isoquinolin-3-yl]ethylurea
{2-[(2E)-9,10-dimethoxy-4-oxo-2-[(2,4,6-trimethylphenyl)imino]-2H,3H,4H,6H,7H-pyrimido[4,3-a]isoquinolin-3-yl]ethyl}urea
2-[4-keto-9,10-dimethoxy-2-(2,4,6-trimethylphenyl)imino-6,7-dihydropyrimido[4,3-a]isoquinolin-3-yl]ethylurea
2-[9,10-dimethoxy-4-oxo-2-(2,4,6-trimethylphenyl)imino-6,7-dihydropyrimido[4,3-a]isoquinolin-3-yl]ethylurea
298680-25-8  CAS
UNII:3E3D8T1GIX

CFTR stimulator; PDE 3 inhibitor; PDE 4 inhibitor

RPL-554 is a mixed phosphodiesterase (PDE) III/IV inhibitor in phase II clinical development at Verona Pharma for the treatment of asthma, allergic rhinitis, chronic obstructive pulmonary disease (COPD) and inflammation.

RPL-554 is expected to have long duration of action and will be administered nasally thereby preventing gastrointestinal problems often resulting from orally administered PDE4 antiinflammatory drugs.

The company is now seeking licensing agreements or partnerships for the further development and commercialization of the drug.

RPL-554 (LS-193,855) is a drug candidate for respiratory diseases. It is an analog of trequinsin, and like trequinsin, is a dual inhibitor of the phosphodiesterase enzymes PDE-3 and PDE-4.[1] As of October 2015, inhaled RPL-554 delivered via a nebulizer was in development for COPD and had been studied in asthma.[2]

PDE3 inhibitors act as bronchodilators, while PDE4 inhibitors have an anti-inflammatory effect.[1][3]

RPL554 was part of a family of compounds invented by Sir David Jack, former head of R&D for GlaxoSmithKline, and Alexander Oxford, a medicinal chemist; the patents on their work were assigned to Vernalis plc.[4][5]:19-20

In 2005, Rhinopharma Ltd, acquired the rights to the intellectual property from Vernalis.[5]:19-20 Rhinopharma was a startup founded in Vancouver, Canada in 2004 by Michael Walker, Clive Page, and David Saint, to discover and develop drugs for chronic respiratory diseases,[5]:16 and intended to develop RPL-554, delivered with an inhaler, first for allergic rhinitis, then asthma, then forCOPD.[5]:16-17 RPL554 was synthesized at Tocris, a contract research organization, under the supervision of Oxford, and was studied in collaboration with Page’s lab at King’s College, London.[1] In 2006 Rhinopharma recapitalized and was renamed Verona Pharma plc.[5]

This was first seen in April 2015 when it was published as a France national. Verona Pharma (formerly Rhinopharma), under license from Kings College via Vernalis, is developing the long-acting bronchodilator, RPL-554 the lead in a series dual inhibitor of multidrug resistant protein-4 and PDE 3 and 4 inhibiting trequinsin analogs which included RPL-565, for treating inflammatory respiratory diseases, such as allergic rhinitis, asthma, and COPD.

RPL554

Verona Pharma’s lead drug, RPL554, is a “first-in-class” inhaled drug under development for chronic obstructive pulmonary disease (COPD), asthma and cystic fibrosis. The drug is an inhibitor of the phosphodiesterase 3 (PDE3) and phosphodiesterase 4 (PDE4) enzymes, two enzymes known to be of importance in the development and progression of immunological respiratory diseases. The drug has the potential to act as both a bronchodilator and an anti-inflammatory which would significantly differentiate it from existing drugs.

RPL554 was selected from a class of compounds co-invented by Sir David Jack, the former Director of Research at Glaxo who led the team that discovered many of the commercially successful drugs in the respiratory market.

Verona Pharma has successfully completed two double-blind placebo controlled randomised Phase 2b studies of RPL554: one in mild to moderate asthma and another in mild to moderate COPD. The drug was found to be well tolerated, free from drug-related adverse effects (especially cardiovascular and gastro-intestinal effects) and generated significant bronchodilation.  Additionally, double-blind placebo controlled exploratory studies in healthy volunteers challenged with an inhaled irritant also generated consistent, clinically meaningful anti-inflammatory effects.

Verona Pharma is also carrying out exploratory studies to investigate the potential of RPL554 as a novel treatement for cystic fibrosis. In November 2014, the Company received a Venture and Innovation Award from the UK Cystic Fibrosis Trust to further such studies.

For further information on the potential of RPL554 for the treatment of respiratory diseases, refer to the peer-reviewed paper available on-line in the highly-respected medication journal, The Lancet Respiratory Medicine, entitledEfficacy and safety of RPL554, a dual PDE3 and PDE4 inhibitor, in healthy volunteers and in patients with asthma or chronic obstructive pulmonary disease: findings from four clinical trials”.

The competitive advantages of RPL554 include the following:
  • combining bronchodilator (PDE 3) and anti-inflammatory actions (PDE 4) in a single drug, something that is currently only achieved with a combination LABA and glucocorticosteroid inhaler,
  • unique in not using steroids or beta agonists, which have known side effects,
  • planned to be administered by nasal inhalation, thereby reducing the unwanted gastrointestinal side effects of many orally administered drugs.
History of Clinical Trials
  • Following completion in May 2008 of toxicological studies of RPL554, the Company commenced in February 2009 a Phase I/IIa clinical trial of the drug at the Centre for Human Drug Research (CHDR) at Leiden in the Netherlands. In September 2009, the Company announced that it had successfully completed the trial, demonstrating that RPL554 has a good safety profile and has beneficial effects in terms of bronchodilation and bronchoprotection in asthmatics and a reduction in the numbers of inflammatory cells in the nasal passages of allergic rhinitis patients.
  • In November 2010, the Company successfully completed a further trial that examined the safety and bronchodilator effectiveness of the drug administered at higher doses.
  • In August 2011, the Company demonstrated that bronchodilation is maintained over a period of 6 days with daily dosing of RPL554 in asthmatics.
  • In November 2011, the Company successfully demonstrated safety and bronchodilation of RPL554 in patients with mild to moderate forms of COPD.
  • In March 2013, the Company demonstrated positive airway anti-inflammatory activity with respect to COPD at a clinical trial carried out at the Medicines Evaluation Unit (MEU) in Manchester, UK.

Synthesis

WO 2000058308

STR1

Cyclization of 1-(3,4-dimethoxyphenethyl)barbituric acid  in refluxing POCl3 produces the pyrimidoisoquinolinone , which is further condensed with 2,4,6-trimethylaniline  in boiling isopropanol to afford the trimethylphenylimino derivative . Subsequent alkylation of with N-(2-bromoethyl)phthalimide in the presence of K2CO3 and KI, followed by hydrazinolysis of the resulting phthalimidoethyl compound  yields the primary amine . This is finally converted into the title urea RPL 554 by reaction with sodium cyanate in aqueous HCl.

Example 1 : 9 Λ 0-Dimethoxy-2-(2.4-6-trimethy-phen yliminoY-3-(N-carbamoyl-2- aminoethylV3.4.6.7-tetrahydro-2H-pyrimido[6.1-a]isoquinolin-4-one

Figure imgf000029_0001

Sodium cyanate (6.0g, 0.092 mol) in water (100 ml) was added dropwise to a stirred solution of 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(2-aminoethyl)-3,4,6,7- tetrahydro-2H-pyrimido[6,l-a]isoquinolin-4-one, prepared according to Preparation 4 above (20.0g, 0.046 mol) in water (600 ml) and IN ΗC1 (92 ml) at 80°C. After stirring for 2h at 80°C the mixture was cooled in an ice-bath and basified with 2N NaOH. The mixture was extracted with dichloromethane (3 x 200 ml) and the combined extract was dried (MgSO- ) and evaporated in vacuo. The resulting yellow foam was purified by column chromatography on silica gel eluting with CH2CI2 / MeOH (97:3) and triturated with ether to obtain the title compound as a yellow solid, 11.9g, 54%.

M.p.: 234-236°C m/z: C26H31N5O4 requires M=477 found (M+l) = 478

HPLC: Area (%) 99.50 Column ODS (150 x 4.6 mm)

MP pH3 KH2PO4 / CH3CN (60/40)

FR (ml/min) 1.0 RT (min) 9.25 Detection 250 nm

lK NMR (300 MHz, CDCI3): δ 1.92 (1H, br s, NH), 2.06 (6H, s, 2xCH3), 2.29 (3H, s, CH3), 2.92 (2H, t, CH2), 3.53 (2H, m, CH2), 3.77 (3H, s, OCH3), 3.91 (3H, s, OCH3), 4.05 (2H, t, CH2), 4.40 (2H, t, CH2), 5.35 (2H, br s, NH2), 5.45 (1H, s, C=CH), 6.68 (1H, s, ArH), 6.70 (1H, s, ArH), 6.89 (2H, s, 2xArH).

Preparation 1 : Synthesis of 2-Chloro-6.7-d-hydro-9.10-Dimethoxy-4H-pyrimido- [6,l-a]isoquinoHn-4-one (shown as (1) in Figure 1

Figure imgf000027_0001

A mixture of l-(3,4-dimethoxyphenyl) barbituric acid (70g, 0.24mol), prepared according to the method described in B. Lai et al. J.Med.Chem. 27 1470-1480 (1984), and phosphorus oxychloride (300ml, 3.22mol) was refluxed for 2.5h. The excess phosphorous oxychloride was removed by distillation (20mmHg) on wa ming. After cooling the residue was slurried in dioxan (100ml) and cautiously added to a vigorously stirred ice/water solution (11). Chloroform (11) was added and the resulting mixture was basified with 30% sodium hydroxide solution. The organic layer was separated and the aqueous phase further extracted with chloroform (2x750ml). The combined organic extracts were washed with water (1.51), dried over magnesium sulphate and concentrated in vacuo to leave a gummy material (90g). This was stirred in methanol for a few minutes, filtered and washed with methanol (200ml), diethyl ether (2x200ml) and dried in vacuo at 40°C to yield the title compound as a yellow/orange solid. 47g, 62%

(300MHz, CDCI3) 2.96(2H, t, C(7) H2); 3.96(6H, s, 2xOCH3; 4.20(2H, t, C(6) H2); 6.61(1H, s, C(1) H); 6.76(1H, s, Ar-H); 7.10(1H, s, Ar-H). Preparation 2: 9.10-Dimethoxy-2-(2.4.6-trimethylphenyliminoV3.4.6.7- tetrahydro-2H-pyrimido[6.1-a]isoquinolin-4-one (shown as (2) in Figure 1

2-Chloro-9,10-dimethoxy-6,7-dihydro-4H-pyrimido[6,l-a]isoquinolin-4-one, prepared according to Preparation 1, (38.5g, 0.13 mol) and 2,4,6-trimethylaniline (52.7g, 0.39 mol) in propan-2-ol (3 1) was stirred and heated at reflux, under nitrogen, for 24h. After cooling to room temperature, the solution was evaporated in vacuo and the residue was purified by column chromatography on silica gel, eluting with CΗ2CI2 /

MeOH, initially 98:2, changing to 96:4 once the product began to elute from the column. The title compound was obtained with a slight impurity, (just above the product on tic). Yield 34.6g, 67%.

Preparation 3: 9.10-Dimethoxy-2-(2.4.6-trimethylphenyliminoV3-(2-N- phthalimidoethyπ-3.4.6.7-tetrahydro-2H-pyrimido[6.1-a]isoquinolin-4-one

(shown as (3 in Figure 1)

A mixture of 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3,4,6,7-tetrahydro-2H- pyrimido[6,l-a]isoquinolin-4-one (which was prepared according to Preparation 2) (60.0g, 0.153 mol), potassium carbonate (191g, 1.38 mol), sodium iodide (137g, 0.92 mol) and N-(2-bromoethyl)phthalimide (234g, 0.92 mol) in 2-butanone (1500 ml) was stirred and heated at reflux, under nitrogen, for 4 days. After cooling to room temperature the mixture was filtered and the filtrate was evaporated in vacuo. The residue was treated with methanol (1000 ml) and the solid filtered off, washed with methanol and recrystallised from ethyl acetate to obtain the title compound as a pale yellow solid in yield 40. Og, 46%. Evaporation of the mother liquor and column chromatography of the residue on silica gel (CΗ2C-2 / MeOH 95:5) provided further product 11.7g, 13.5%. Preparation 4: 9.10-Dimethoxy-2-(2A6-trimethylphenylimino)-3-(2-arninoethyO- 3.4.6.7-tetrahydro-2H-pyrimido[6.1-a]isoquino-in-4-one (shown as (4) in Figure 1)

A mixture of 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(2-N- phthalimidoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,l-a]isoquinolin-4-one (22. Og, 0.039 mol), prepared according to Preparation 3, and hydrazine hydrate (11.3g, 0.195 mol) in chloroform (300 ml) and ethanol (460 ml) was stined at room temperature, under nitrogen, for 18h. Further hydrazine hydrate (2.9g, 0.05 mol) was added and the mixture was stirred a further 4h. After cooling in ice / water, the solid was removed by filtration and the filtrate evaporated in vacuo. The residue was dissolved in dichloromethane and the insoluble material was removed by filtration. The fitrate was dried (MgSO-i) and evaporated in vacuo to afford the title compound as a yellow foam in yield 16.2g, 96%.

PATENT

WO-2016128742

Novel crystalline acid addition salts forms of RPL-554 are claimed, wherein the salts, such as ethane- 1,2-disulfonic acid, ethanesulfonic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, hydrochloric acid, hydrobromic acid, phosphoric acid or sulfuric acid. .

RPL554 (9, 10-dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(/V-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6, l-a]isoquinolin-4-one) is a dual PDE3/PDE4 inhibitor and is described in WO 00/58308. As a combined PDE3/PDE4 inhibitor, RPL554 has both antiinflammatory and bronchodilatory activity and is useful in the treatment of respiratory disorders such as asthma and chronic obstructive pulmonary disease (COPD). The structure of RPL554 is shown below.

Owing to its applicability in the treatment of respiratory disorders, it is often preferable to administer RPL554 by inhalation. Franciosi et al. disclose a solution of RPL554 in a citrate-phosphate buffer at pH 3.2 (The Lancet: Respiratory Medicine 11/2013; l(9):714-27. DOI: 10.1016/S2213-2600(13)70187-5). The preparation of salts of RPL554 has not been described.

PATENT

http://www.google.ch/patents/WO2000058308A1?cl=en&hl=de

PATENT

http://www.google.ch/patents/WO2012020016A1?cl=en

U.S. Pat. No. 6,794,391, 7,378,424, and 7,105,663, which are each incorporated herein by reference, discloses compound RPL-554 (N-{2-[(2iT)-2-(mesityiimino)-9,10- dimethoxy-4-oxo-6,7-dihydro-2H-pyrimido[6,l-a]-isoquinolin-3 4H)-yl]ethyl}urea).

Figure imgf000003_0001

It would be beneficial to provide a composition of a stable polymorph of RPL-554, that has advanrtages over less stable polymorphs or amorphous forms, including

stability, compressibility, density, dissolution rates, increased potency or. lack toxicity.

WO2000058308A1 * Mar 29, 2000 Oct 5, 2000 Vernalis Limited DERIVATIVES OF PYRIMIDO[6,1-a]ISOQUINOLIN-4-ONE
US6794391 Sep 26, 2001 Sep 21, 2004 Vernalis Limited Derivatives of pyrimido[6.1-a]isoquinolin-4-one
US7105663 Feb 24, 2004 Sep 12, 2006 Rhinopharma Limited Derivatives of pyrimido[6,1-a]isoquinolin-4-one
US7378424 Feb 24, 2004 May 27, 2008 Verona Pharma Plc Derivatives of pyrimido[6, 1-A]isoquinolin-4-one
Patent ID Date Patent Title
US7378424 2008-05-27 Derivatives of pyrimido[6, 1-A]isoquinolin-4-one
US7105663 2006-09-12 Derivatives of pyrimido[6, 1-a]isoquinolin-4-one
US6794391 2004-09-21 Derivatives of pyrimido[6.1-a]isoquinolin-4-one
US2004001895 2004-01-01 Combination treatment for depression and anxiety
US2003235631 2003-12-25 Combination treatment for depression and anxiety
Patent ID Date Patent Title
US2015210655 2015-07-30 CERTAIN (2S)-N-[(1S)-1-CYANO-2-PHENYLETHYL]-1, 4-OXAZEPANE-2-CARBOXAMIDES AS DIPEPTIDYL PEPTIDASE 1 INHIBITORS
US2014349969 2014-11-27 COMPOUNDS AND METHODS FOR TREATING PAIN
US2014242174 2014-08-28 TREATING COUGH AND TUSSIVE ATTACKS
US2013252924 2013-09-26 Compounds and Methods for Treating Pain
US2013225616 2013-08-29 CRYSTALLINE FORM OF PYRIMIDIO[6, 1-A] ISOQUINOLIN-4-ONE COMPOUND
US2012302533 2012-11-29 DERIVATIVES OF PYRIMIDO [6, 1-A] ISOQUINOLIN-4-ONE
US8242127 2012-08-14 Derivatives of pyrimido[6, 1-A]isoquinolin-4-one
US2011201665 2011-08-18 Compositions, Methods, and Kits for Treating Influenza Viral Infections
US2011028510 2011-02-03 Compositions, Methods, and Kits for Treating Influenza Viral Infections
US2010260755 2010-10-14 IBUDILAST AND IMMUNOMODULATORS COMBINATION
WO2012020016A1 * 9. Aug. 2011 16. Febr. 2012 Verona Pharma Plc Crystalline form of pyrimidio[6,1-a]isoquinolin-4-one compound
WO2014140647A1 17. März 2014 18. Sept. 2014 Verona Pharma Plc Drug combination
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References

  1. Boswell-Smith V et al. The pharmacology of two novel long-acting phosphodiesterase 3/4 inhibitors, RPL554 [9,10-dimethoxy-2(2,4,6-trimethylphenylimino)-3-(n-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one] and RPL565 [6,7-dihydro-2-(2,6-diisopropylphenoxy)-9,10-dimethoxy-4H-pyrimido[6,1-a]isoquinolin-4-one]. J Pharmacol Exp Ther. 2006 Aug;318(2):840-8. PMID 16682455
  2.  Nick Paul Taylor for FierceBiotech. October 1, 2015 Verona sets sights on PhIIb after COPD drug comes through early trial
  3.  Turner MJ et al. The dual phosphodiesterase 3 and 4 inhibitor RPL554 stimulates CFTR and ciliary beating in primary cultures of bronchial epithelia. Am J Physiol Lung Cell Mol Physiol. 2016 Jan 1;310(1):L59-70. PMID 26545902
  4. Jump up^ see US20040171828, identified in the citations of PMID 16682455
  5. ISIS Resources, PLC. August 23, 2006 Proposed Acquisition of Rhinopharma

REFERENCES

1: Calzetta L, Cazzola M, Page CP, Rogliani P, Facciolo F, Matera MG. Pharmacological characterization of the interaction between the dual phosphodiesterase (PDE) 3/4 inhibitor RPL554 and glycopyrronium on human isolated bronchi and small airways. Pulm Pharmacol Ther. 2015 Jun;32:15-23. doi: 10.1016/j.pupt.2015.03.007. Epub 2015 Apr 18. PubMed PMID: 25899618.

2: Franciosi LG, Diamant Z, Banner KH, Zuiker R, Morelli N, Kamerling IM, de Kam ML, Burggraaf J, Cohen AF, Cazzola M, Calzetta L, Singh D, Spina D, Walker MJ, Page CP. Efficacy and safety of RPL554, a dual PDE3 and PDE4 inhibitor, in healthy volunteers and in patients with asthma or chronic obstructive pulmonary disease: findings from four clinical trials. Lancet Respir Med. 2013 Nov;1(9):714-27. doi: 10.1016/S2213-2600(13)70187-5. Epub 2013 Oct 25. PubMed PMID: 24429275.

3: Wedzicha JA. Dual PDE 3/4 inhibition: a novel approach to airway disease? Lancet Respir Med. 2013 Nov;1(9):669-70. doi: 10.1016/S2213-2600(13)70211-X. Epub 2013 Oct 25. PubMed PMID: 24429260.

4: Calzetta L, Page CP, Spina D, Cazzola M, Rogliani P, Facciolo F, Matera MG. Effect of the mixed phosphodiesterase 3/4 inhibitor RPL554 on human isolated bronchial smooth muscle tone. J Pharmacol Exp Ther. 2013 Sep;346(3):414-23. doi: 10.1124/jpet.113.204644. Epub 2013 Jun 13. PubMed PMID: 23766543.

5: Gross N. The COPD pipeline XX. COPD. 2013 Feb;10(1):104-6. doi: 10.3109/15412555.2013.766103. PubMed PMID: 23413896.

6: Gross NJ. The COPD Pipeline XIV. COPD. 2012 Feb;9(1):81-3. doi: 10.3109/15412555.2012.646587. PubMed PMID: 22292600.

7: Boswell-Smith V, Spina D, Oxford AW, Comer MB, Seeds EA, Page CP. The pharmacology of two novel long-acting phosphodiesterase 3/4 inhibitors, RPL554 [9,10-dimethoxy-2(2,4,6-trimethylphenylimino)-3-(n-carbamoyl-2-aminoethyl)-3,4,6, 7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one] and RPL565 [6,7-dihydro-2-(2,6-diisopropylphenoxy)-9,10-dimethoxy-4H-pyrimido[6,1-a]isoquino lin-4-one]. J Pharmacol Exp Ther. 2006 Aug;318(2):840-8. Epub 2006 May 8. PubMed PMID: 16682455.

RPL-554
RPL554.png
Systematic (IUPAC) name
N-{2-[(2E)-2-(mesitylimino)-9,10-dimethoxy-4-oxo-6,7-dihydro-2H-pyrimido[6,1-a]-isoquinolin-3(4H)-yl]ethyl}urea
Identifiers
PubChem CID 9934746
ChemSpider 8110374 Yes
Synonyms 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one
Chemical data
Formula C26H31N5O4
Molar mass 477.554 g/mol

///////////RPL-554, LS-193,855, 298680-25-8, UNII:3E3D8T1GIX, RPL554, RPL 554, phase 2, Chronic Obstructive Pulmonary Diseases , COPD, Allergic Rhinitis, Asthma Therapy, Cystic Fibrosis, Inflammation, Bronchodilators

Cc3cc(C)cc(C)c3N=c2cc1-c(cc4OC)c(cc4OC)CCn1c(=O)n2CCNC(N)=O

ACT-334441, Cenerimod an S1P receptor 1 agonist


img

ACT-334441

Cenerimod

UNII-Y333RS1786; Y333RS1786

S1P receptor 1 agonist

CAS 1262414-04-9
Chemical Formula: C25H31N3O5
Exact Mass: 453.22637

Actelion Pharmaceuticals Ltd.

Martin Bolli, Cyrille Lescop, Boris Mathys,Keith Morrison, Claus Mueller, Oliver Nayler,Beat Steiner,

(S)-3-(4-(5-(2-cyclopentyl-6-methoxypyridin-4-yl)-1,2,4-oxadiazol-3-yl)-2-ethyl-6-methylphenoxy)propane-1,2-diol

(2S)-3-[4-[5-(2-cyclopentyl-6-methoxypyridin-4-yl)-1,2,4-oxadiazol-3-yl]-2-ethyl-6-methylphenoxy]propane-1,2-diol

(S)-3-{4-[5-(2-Cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4]oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol

Mechanism Of Action Sphingosine 1 phosphate receptor modulator
Who Atc Codes L03A-X (Other immunostimulants)
Ephmra Codes L3A (Immunostimulating Agents Excluding Interferons)
Indication Systemic Lupus Erythematosus

Cenerimod is a potent and orally active immunomodulator, exhibited EC50 value of 2.7 nM. Cenerimod is an agonist for the G protein-coupled receptor S1 P1/EDG1 and has a powerful and long-lasting immunomodulating effect which is achieved by reducing the number of circulating and infiltrating T- and B-lymphocytes, without affecting their maturation, memory, or expansion. Cenerimod may be useful for prevention or treatment of diseases associated with an activated immune system

CENERIMOD

ACT-334441; lysosphingolipid receptor agonist – Actelion; S1P1 receptor modulator – Actelion; Second selective S1P1 receptor agonist – Actelion; Sphingosine 1 phosphate receptor modulators – Actelion; Sphingosine 1-phosphate receptor 1 agonists – Actelion

  • Mechanism of Action Lysosphingolipid receptor agonists
  • Highest Development Phases
  • Phase I/II Systemic lupus erythematosus

Most Recent Events

  • 09 Jun 2016 Actelion terminates a phase I drug interaction trial for Systemic lupus erythematosus (In volunteers) in France (NCT02479204)
  • 22 Dec 2015 Phase-I/II clinical trials in Systemic lupus erythematosus in Ukraine, Belarus (PO) (NCT02472795)
  • 24 Sep 2015 Phase-I/II clinical trials in Systemic lupus erythematosus in USA (PO) (NCT02472795)
# Nct Number Title Recruitment Conditions Interventions Phase
1 NCT02472795 Clinical Study to Investigate the Biological Activity, Safety, Tolerability, and Pharmacokinetics of ACT-334441 in Subjects With Systemic Lupus Erythematosus Recruiting Systemic Lupus Erythematosus Drug: ACT-334441|Drug: Placebo Phase 2 Actelion
2 NCT02479204 Drug Interaction Study of ACT-334441 With Cardiovascular Medications in Healthy Subjects Suspended Healthy Subjects Drug: ACT-334441 2 mg|Drug: ACT-334441 4 mg|Drug: placebo|Drug: atenolol|Drug: diltiazem ER Phase 1 Actelion

str1

UNII-Y333RS1786.png

STR2 STR3

The human immune system is designed to defend the body against foreign micro-organisms and substances that cause infection or disease. Complex regulatory mechanisms ensure that the immune response is targeted against the intruding substance or organism and not against the host. In some cases, these control mechanisms are unregulated and autoimmune responses can develop. A consequence of the uncontrolled inflammatory response is severe organ, cell, tissue or joint damage. With current treatment, the whole immune system is usually suppressed and the body’s ability to react to infections is also severely compromised. Typical drugs in this class include azathioprine, chlorambucil, cyclophosphamide, cyclosporin, or methotrexate. Corticosteroids which reduce inflammation and suppress the immune response, may cause side effects when used in long term treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce pain and inflammation, however, they exhibit considerable side effects. Alternative treatments include agents that activate or block cytokine signaling.

Orally active compounds with immunomodulating properties, without compromising immune responses and with reduced side effects would significantly improve current treatments of uncontrolled inflammatory diseases.

In the field of organ transplantation the host immune response must be suppressed to prevent organ rejection. Organ transplant recipients can experience some rejection even when they are taking immunosuppressive drugs. Rejection occurs most frequently in the first few weeks after transplantation, but rejection episodes can also happen months or even years after transplantation. Combinations of up to three or four medications are commonly used to give maximum protection against rejection while minimizing side effects. Current standard drugs used to treat the rejection of transplanted organs interfere with discrete intracellular pathways in the activation of T-type or B-type white blood cells. Examples of such drugs are cyclosporin, daclizumab, basiliximab, everolimus, or FK506, which interfere with cytokine release or signaling; azathioprine or leflunomide, which inhibit nucleotide synthesis; or 15-deoxyspergualin, an inhibitor of leukocyte differentiation.

The beneficial effects of broad immunosuppressive therapies relate to their effects; however, the generalized immunosuppression which these drugs produce diminishes the immune system’s defense against infection and malignancies. Furthermore, standard immunosuppressive drugs are often used at high dosages and can cause or accelerate organ damage.

SYNTHESIS

STR1

PATENT

https://www.google.com/patents/WO2011007324A1?cl=zh

The human immune system is designed to defend the body against foreign microorganisms and substances that cause infection or disease. Complex regulatory mechanisms ensure that the immune response is targeted against the intruding substance or organism and not against the host. In some cases, these control mechanisms are unregulated and autoimmune responses can develop. A consequence of the uncontrolled inflammatory response is severe organ, cell, tissue or joint damage. With current treatment, the whole immune system is usually suppressed and the body’s ability to react to infections is also severely compromised. Typical drugs in this class include azathioprine, chlorambucil, cyclophosphamide, cyclosporin, or methotrexate. Corticosteroids which reduce inflammation and suppress the immune response, may cause side effects when used in long term treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce pain and inflammation, however, they exhibit considerable side effects. Alternative treatments include agents that activate or block cytokine signaling.

Orally active compounds with immunomodulating properties, without compromising immune responses and with reduced side effects would significantly improve current treatments of uncontrolled inflammatory diseases.

In the field of organ transplantation the host immune response must be suppressed to prevent organ rejection. Organ transplant recipients can experience some rejection even when they are taking immunosuppressive drugs. Rejection occurs most frequently in the first few weeks after transplantation, but rejection episodes can also happen months or even years after transplantation. Combinations of up to three or four medications are commonly used to give maximum protection against rejection while minimizing side effects. Current standard drugs used to treat the rejection of transplanted organs interfere with discrete intracellular pathways in the activation of T-type or B-type white blood cells. Examples of such drugs are cyclosporin, daclizumab, basiliximab, everolimus, or FK506, which interfere with cytokine release or signaling; azathioprine or leflunomide, which inhibit nucleotide synthesis; or 15-deoxyspergualin, an inhibitor of leukocyte differentiation.

The beneficial effects of broad immunosuppressive therapies relate to their effects; however, the generalized immunosuppression which these drugs produce diminishes the immune system’s defense against infection and malignancies. Furthermore, standard immunosuppressive drugs are often used at high dosages and can cause or accelerate organ damage.

Description of the invention

The present invention provides novel compounds of Formula (I) that are agonists for the G protein-coupled receptor S1 P1/EDG1 and have a powerful and long-lasting immunomodulating effect which is achieved by reducing the number of circulating and infiltrating T- and B-lymphocytes, without affecting their maturation, memory, or expansion. The reduction of circulating T- / B-lymphocytes as a result of S1 P1/EDG1 agonism, possibly in combination with the observed improvement of endothelial cell layer function associated with S1 P1/EDG1 activation, makes such compounds useful to treat uncontrolled inflammatory diseases and to improve vascular functionality. Prior art document WO 2008/029371 discloses compounds that act as S1 P1/EDG1 receptor agonists and show an immunomodulating effect as described above. Unexpectedly, it has been found that the compounds of the present invention have a reduced potential to constrict airway tissue/vessels when compared to compounds of the prior art document WO 2008/029371. The compounds of the present invention therefore demonstrate superiority with respect to their safety profile, e.g. a lower risk of bronchoconstriction.

Examples of WO 2008/029371 , which are considered closest prior art analogues are shown in Figure 1.

Figure imgf000004_0001

Figure 1 : Structure of Examples of prior art document WO 2008/029371 , which are considered closest analogues to the compounds of the present invention.

The data on the constriction of rat trachea rings compiled in Table 1 illustrate the superiority of the compounds of the present invention as compared to compounds of prior art document WO 2008/029371.

For instance, the compounds of Example 1 and 6 of the present invention show a significantly reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 222 and 226 of WO 2008/029371 , respectively. Furthermore, the compounds of Example 1 and 6 of the present invention also show a reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 196 and 204 of WO 2008/029371 , respectively. These data demonstrate that compounds wherein R1 represents 3-pentyl and R2 represents methoxy are superior compared to the closest prior art compounds of WO 2008/029371 , i.e. the compounds wherein R1 represents an isobutyl and R2 represents methoxy or wherein R1represents methyl and R2 represents 3-pentyl. Moreover, also the compound of Example 16 of the present invention, wherein R1 is 3-methyl-but-1-yl and R2 is methoxy, exhibits a markedly reduced potential to constrict rat trachea rings when compared to its closest analogue prior art Example 226 of WO 2008/029371 wherein R1 is isobutyl and R2 is methoxy.

The unexpected superiority of the compounds of the present invention is also evident from the observation that the compounds of Example 2 and 7 of the present invention show a markedly reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 229 and 233 of WO 2008/029371 , respectively. This proves that compounds wherein R1represents cyclopentyl and R2 represents methoxy are superior compared to the closest prior art compounds of WO 2008/029371 , i.e. the compounds wherein R1 represents methyl and R2 represents cyclopentyl.

Also, the compound of Example 3 of the present invention exhibits the same low potential to constrict rat trachea rings as its S-enantiomer, i.e. the compound of Example 2 of the present invention, indicating that the configuration at this position has no significant effect on trachea constriction. Furthermore, also Example 21 of the present invention exhibits the same low potential to constrict rat trachea rings as present Example 2, which differs from Example 21 only by the linker A (forming a 5-pyridin-4-yl-[1 ,2,4]oxadiazole instead of a 3- pyridin-4-yl-[1 ,2,4]oxadiazole). This indicates that also the nature of the oxadiazole is not critical regarding trachea constriction.

Table 1 : Rat trachea constriction in % of the constriction induced by 50 mM KCI. n.d. = not determined. For experimental details and further data see Example 33.

Figure imgf000005_0001
Figure imgf000006_0002

result obtained at a compound concentration of 300 nM.

The compounds of the present invention can be utilized alone or in combination with standard drugs inhibiting T-cell activation, to provide a new immunomodulating therapy with a reduced propensity for infections when compared to standard immunosuppressive therapy. Furthermore, the compounds of the present invention can be used in combination with reduced dosages of traditional immunosuppressant therapies, to provide on the one hand effective immunomodulating activity, while on the other hand reducing end organ damage associated with higher doses of standard immunosuppressive drugs. The observation of improved endothelial cell layer function associated with S1 P1/EDG1 activation provides additional benefits of compounds to improve vascular function.

The nucleotide sequence and the amino acid sequence for the human S1 P1/EDG1 receptor are known in the art and are published in e.g.: HIa, T., and Maciag, T., J. Biol

Chem. 265 (1990), 9308-9313; WO 91/15583 published 17 October 1991 ; WO 99/46277 published 16 September 1999. The potency and efficacy of the compounds of Formula (I) are assessed using a GTPγS assay to determine EC5O values and by measuring the circulating lymphocytes in the rat after oral administration, respectively (see in experimental part). i) In a first embodiment, the invention relates to pyridine compounds of the Formula (I),

Figure imgf000006_0001

Formula (I)

PATENT

WO 2013175397

https://www.google.com/patents/WO2013175397A1?cl=en

Pyridine-4-yl derivatives of formula (PD),

Figure imgf000002_0001

Formula (PD) A represents

Figure imgf000002_0002

(the asterisks indicate the bond that is linked to the pyridine group of Formula (PD));

Ra represents 3-pentyl, 3-methyl-but-1-yl, cyclopentyl, or cyclohexyl;

Rb represents methoxy;

Rc represents 2,3-dihydroxypropoxy, -OCH2-CH(OH)-CH2-NHCO-CH2OH,

-OCH2-CH(OH)-CH2N(CH3)-CO-CH2OH, -NHS02CH3, or -NHS02CH2CH3; and

Rd represents ethyl or chloro.)

disclosed in WO201 1007324, have immunomodulating activity through their S1 P1/EDG1 receptor agonistic activity. Therefore, those pyridine-4-yl derivatives are useful for prevention and / or treatment of diseases or disorders associated with an activated immune system, including rejection of transplanted organs such as kidney, liver, heart, lung, pancreas, cornea, and skin; graft-versus-host diseases brought about by stem cell transplantation; autoimmune syndromes including rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, psoriasis, psoriatic arthritis, thyroiditis such as Hashimoto’s thyroiditis, uveo-retinitis; atopic diseases such as rhinitis, conjunctivitis, dermatitis; asthma; type I diabetes; post-infectious autoimmune diseases including rheumatic fever and post-infectious glomerulonephritis; solid cancers and tumor metastasis. 2-Cyclopentyl-6-methoxy-isonicotinic acid, which is also disclosed in WO201 1007324, is a useful intermediate for the synthesis of the pyridine-4-yl derivatives of formula (PD), wherein Ra is a cyclopentyl group.

In the process described in WO201 1007324, 2-cyclopentyl-6-methoxy-isonicotinic acid was prepared according to the following reaction scheme 1 :

Figure imgf000003_0001

Compound D Compound E

Rieke Zinc: cyclopentylzinc bromide;

PdCI2(dppf)dcm: 1 ,1 ‘-Bis(diphenylphosphino)ferrocene-palladium(ll)dichloride

dichloromethane complex

However, the abovementioned process has drawbacks for larger scale, i.e. industrial scale synthesis of 2-cyclopentyl-6-methoxy-isonicotinic acid, for the following reasons:

a) The commercially available starting material, 2,6-dichloro-isonicotinic acid (Compound A) is expensive.

b) The conversion of Compound C to Compound D is cost-intensive. The reaction has to be performed under protective atmosphere with expensive palladium catalysts and highly reactive and expensive Rieke zinc complex. Such synthesis steps are expensive to scale up and it was therefore highly desired to find alternative synthesis methods.

Even though Goldsworthy, J. Chem. Soc. 1934, 377-378 discloses the preparation of 1 -cyclopentylethanone, which is a key building block in the new process of the present invention, by using ethyl 1 -acetoacetate as a starting material, this synthesis was far from being suitable in an industrial process. The reported yield was low (see also under “Referential Examples” below). Scheme 2

Figure imgf000004_0001

ethyl 1 -acetylcyclo- 1-cyclopentyl- pentanecarboxylate ethanone

Besides the early work by Goldsworthy there are several recent examples for the preparation of 1 -cyclopentylethanone described in the literature. Such examples include:

1 ) Addition of methyl lithium to a N-cyclopentanecarbonyl-N,0-dimethylhydroxylamine at -78°C in a yield of 77%. US2006/199853 A1 , 2006 and US2006/223884 A1 , 2006.

2) Addition of methyl lithium to a cyclopentyl carboxylic acid in diethylether at -78°C in a yield of 81 %. J. Am. Chem. Soc, 1983, 105, 4008-4017.

3) Addition of methylmagnesiumbromide to cyclopentanecarbonitrile.

Bull. Soc. Chim. Fr., 1967, 3722-3729.

4) Oxidation of 1 -cyclopentylethanol with chromtrioxide. US5001 140 A1 , 1991.

WO2009/71707 A1 , 2009.

5) Addition of cyclopentylmagnesium bromide to acetic anhydride at -78 °C with a yield of 54%. WO2004/74270 A2, 2004.

6) Synthesis of 1-cyclopentylethanone in 5 steps from cyclopentanone. Zhang, Pang; Li, Lian-chu, Synth. Commun., 1986, 16, 957-966.

However, the processes described in the above-listed publications are not efficient for scale-up since they require cryogenic temperatures, expensive starting materials, toxic reagents or many steps. The lack of an efficient process to manufacture 1 -cyclopentylethanone is further also mirrored by the difficulty in sourcing this compound on kilogram scale for a reasonable price and delivery time. Therefore, the purpose of the present invention is to provide a new, efficient and cost effective process for the preparation of 2-cyclopentyl-6-methoxy-isonicotinic acid, which is suitable for industrial scale synthesis.

Patent

https://patentscope.wipo.int/search/en/detail.jsf?docId=US133347630&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

Disclosed in WO2011007324, have immunomodulating activity through their S1P1/EDG1 receptor agonistic activity. Therefore, those pyridine-4-yl derivatives are useful for prevention and/or treatment of diseases or disorders associated with an activated immune system, including rejection of transplanted organs such as kidney, liver, heart, lung, pancreas, cornea, and skin; graft-versus-host diseases brought about by stem cell transplantation; autoimmune syndromes including rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, psoriasis, psoriatic arthritis, thyroiditis such as Hashimoto’s thyroiditis, uveo-retinitis; atopic diseases such as rhinitis, conjunctivitis, dermatitis; asthma; type I diabetes; post-infectious autoimmune diseases including rheumatic fever and post-infectious glomerulonephritis; solid cancers and tumor metastasis. 2-Cyclopentyl-6-methoxy-isonicotinic acid, which is also disclosed in WO2011007324, is a useful intermediate for the synthesis of the pyridine-4-yl derivatives of formula (PD), wherein Ra is a cyclopentyl group.

      In the process described in WO2011007324, 2-cyclopentyl-6-methoxy-isonicotinic acid was prepared according to the following reaction scheme 1:

Rieke Zinc: cyclopentylzinc bromide;
PdCl2(dppf)dcm: 1,1′-Bis(diphenylphosphino)ferrocene-palladium(II)dichloride dichloromethane complex

EXAMPLES

Example 1a

1-Cyclopentylethanone


      A mixture of 1,4 dibromobutane (273 g, 1 eq.), tetrabutylammonium bromide (20 g, 0.05 eq.) in 32% NaOH (1 L) was heated to 50° C. Tert.-butyl acetoacetate (200 g, 1 eq.) was added keeping the maximum internal temperature below 55° C. The mixture was stirred for 5 h at 50° C. The stirrer was stopped and the org. layer was separated. The org. layer was washed with 1N HCl (500 mL). The org. layer was added to 32% HCl (300 mL) at an external temperature of 60° C. The mixture was stirred at 60° C. for 3.5 h and cooled to 40° C. The mixture was washed with brine (60 mL). The org. layer was washed with brine (150 mL) and dried with magnesium sulphate (8 g). The mixture was filtered and the product was purified by distillation (distillation conditions: external temperature: 70° C., head temperature: 40-55° C., pressure: 30-7 mbar) to obtain a colourless liquid; yield: 107 g (75%). Purity (GC-MS): 99.8% a/a; GC-MS: tR=1.19 min, [M+1]+=113. 1H NMR (CDCl3): δ=2.86 (m, 1H), 2.15 (s, 3H), 1.68 (m, 8H).

Example 1 b

1-Cyclopentylethanone

      Tert-butyl 1-acetylcyclopentanecarboxylate (723 g, 3.41 mol) was added to 32% HCl (870 mL) at an internal temperature of 80° C. over a period of 2 h. The mixture was stirred at 80° C. for 1 h and cooled to 50° C. The stirrer was stopped and the org. layer was separated. The org. layer was washed with water (250 mL) and dried with magnesium sulphate (24 g). The mixture was filtered and the product was purified by distillation to obtain a colourless liquid; yield: 333.6 g (87%). Purity (GC-MS): 97.3% a/a; GC-MS: tR=1.19 min, [M+1]+=113.

Example 1c

1-Cyclopentylethanone

      Tert-butyl 1-acetylcyclopentanecarboxylate (300 g, 1.41 mol) was added to 5 M HCl in isopropanol (600 mL) at an internal temperature of 60° C. over a period of 25 min. The mixture was stirred at 60° C. for 18 h and cooled to 20° C. Water (1 L) was added, the stirrer was stopped and the org. layer was separated. The org. layer was washed with water (500 mL). The crude product was purified by distillation to obtain a colourless liquid; yield: 115 g (72%). Purity (GC-MS): 87.2% a/a; GC-MS: tR=1.19 min, [M+1]+=113.

Example 1d

1-Cyclopentylethanone

      Tert-butyl 1-acetylcyclopentanecarboxylate (514 g, 2.42 mol) was added to TFA (390 mL) at an internal temperature of 60° C. More TFA (200 mL) was added and the temperature was adjusted to 65° C. The mixture was stirred at 65° C. for 1 h. The reaction mixture was concentrated at 45° C. and 20 mbar. The residue was added to TBME (500 mL), ice (200 g) and 32% NaOH (300 mL). The aq. layer was separated and extracted with TBME (500 mL). The combined org. layers were concentrated to dryness to yield the crude 1-cyclopentylethanone. The crude product was purified by distillation to yield a colorless liquid: 221.8 g (82%). Purity (GC-MS): 90.2% a/a; GC-MS: tR=1.19 min, [M+l]+=113.

Example 1e

1-Cyclopentylethanone

      Tert-butyl 1-acetylcyclopentanecarboxylate (534 g, 2.52 mol) was added to 50% H2SO4 (300 mL) at an internal temperature of 100° C. over a period of 40 min. The mixture was stirred at 120° C. for 2 h and cooled to 20° C. The stirrer was stopped and the org. layer was separated. The org. layer was washed with saturated NaHCO3 solution (250 mL). The crude product was purified by distillation to obtain a colourless liquid; yield: 177 g (63%). Purity (GC-MS): 99.9% a/a; GC-MS: tR=1.19 min, [M+1]+=113.

Example 1f

Tert-butyl 1-acetylcyclopentanecarboxylate


      To a mixture of potassium carbonate (1 kg, 7.24 mol) and tetrabutylammonium iodide (10 g, 0.027 mol) in DMSO (3 L) was added a mixture of 1,4-dibromobutane (700 g, 3.24 mol) and tert.-butyl acetoacetate (500 g, 3.16 mol). The mixture was stirred at 25° C. for 20 h. To the reaction mixture was added water (4 L) and TBME (3 L). The mixture was stirred until all solids dissolved. The TBME layer was separated and washed with water (3×1 L). The org. layer was concentrated and the crude product was purified by distillation (distillation conditions: external temperature: 135° C., head temperature: 105-115° C., pressure: 25-10 mbar) to obtain a colourless liquid; yield: 537.6 g (80%). Purity (GC-MS): 90.5% a/a; GC-MS:
      tR=1.89 min, [M+1]+=213. 1H NMR (CDCl3): δ=2.16 (s, 3H), 2.06 (m, 4H), 1.63 (m, 4H), 1.45 (s, 9H).

Example 1 g

Tert-butyl 1-acetylcyclopentanecarboxylate

      A mixture of 1,4 dibromobutane (281 g, 1 eq.) and tetrabutylammonium bromide (15 g, 0.05 eq.) in 50% NaOH (1 L) was heated to 50° C. Tert.-butyl acetoacetate (206 g, 1 eq.) was added keeping the maximum internal temperature below 55° C. The mixture was stirred for 5 h at 50° C. The stirrer was stopped and the org. layer was separated. The org. layer was washed with 1N HCl (500 mL). The crude product was purified by distillation to obtain a colourless liquid; yield: 199 g (72%). Purity (GC-MS): 97.8% a/a; GC-MS: tR=1.89 min, [M+1]+=213.

Example 2

2-Cyclopentyl-6-hydroxyisonicotinic acid


      A 10 L reactor was charged with potassium tert.-butylate (220 g, 1.1 eq.) and THF (3 L). The solution was cooled to −20° C. A mixture of diethyloxalate (260 g, 1 eq.) and 1-cyclopentylethanone (200 g, 1.78 mol, 1 eq.) was added at a temperature below −18° C. The reaction mixture was stirred at −10° C. for 30 min and then warmed to 15° C. To the mixture was added cyano acetamide (180 g, 1.2 eq.). The mixture was stirred for 20 h at 22° C. Water (600 mL) was added and the reaction mixture was concentrated at 60° C. under reduced pressure on a rotary evaporator. 3.4 L solvent were removed. The reactor was charged with 32% HCl (5 L) and heated to 50° C. The residue was added to the HCl solution at a temperature between 44 and 70° C. The mixture was heated to 100° C. for 22 h. 2.7 L solvent were removed at 135° C. external temperature and a pressure of ca. 400 mbar. The suspension was diluted with water (2.5 L) and cooled to 10° C. The suspension was filtered. The product cake was washed with water (2.5 L) and acetone (3 L). The product was dried to obtain an off white solid; yield: 255 g (69%); purity (LC-MS): 100% a/a; LC-MS: tR=0.964 min, [M+1]+=208; 1H NMR (deutero DMSO): δ=12.67 (br, 2H), 6.63 (s, 1H), 6.38 (s, 1H), 2.89 (m, 1H), 1.98 (m, 2H), 1.63 (m, 6H).

Example 3

Methyl 2-cyclopentyl-6-hydroxyisonicotinate


      2-Cyclopentyl-6-hydroxyisonicotinic acid (1520.5 g, 7.3 mol, 1 eq.), methanol (15.2 L), trimethylorthoformiate (1.56 L, 2 eq.) and sulphuric acid (471 mL, 1.2 eq.) were mixed at 20° C. and heated to reflux for 18 h. 10 L solvent were removed at 95° C. external temperature and a pressure of ca. 800 mbar.
      The mixture was cooled to 20° C. and added to water (7.6 L) at 50° C. The suspension was diluted with water (3.8 L), cooled to 10° C. and filtered. The cake was washed with water (3.8 L). The product was dried to obtain a yellowish solid; yield: 1568 g (97%); purity (LC-MS): 100% a/a; LC-MS: tR=1.158 min, [M+1]+=222; 1H NMR (deutero DMSO) δ=11.98 (br, 1H), 6.63 (m, 1H), 6.39 (s, 1H), 3.83 (s, 3H), 2.91 (m, 1H), 1.99 (m, 2H), 1.72 (m, 2H), 1.58 (m, 4H).

Example 4a

Methyl 2-chloro-6-cyclopentylisonicotinate


      Methyl 2-cyclopentyl-6-hydroxyisonicotinate (50 g, 0.226 mol, 1 eq.) and phenylphosphonic dichloride (70 mL, 2 eq.) were heated to 130° C. for 3 h. The reaction mixture was added to a solution of potassium phosphate (300 g) in water (600 mL) and isopropyl acetate (600 mL) at 0° C. The mixture was filtered over kieselguhr (i.e. diatomite, Celite™) (50 g). The aq. layer was separated and discarded. The org. layer was washed with water (500 mL). The org. layer was concentrated to dryness at 65° C. and reduced pressure to obtain a black oil; yield: 50.4 g (93%); purity (LC-MS): 94% a/a.
      The crude oil was purified by distillation at an external temperature of 130° C., head temperature of 106° C. and oil pump vacuum to yield a colourless oil; yield: 45.6 g (84%); purity (LC-MS): 100% a/a; LC-MS: tR=1.808 min, [M+1]+=240; 1H NMR (CDCl3) δ=7.69 (s, 1H), 7.67 (s, 1H), 3.97 (s, 3H), 3.23 (m, 1H), 2.12 (m, 2H), 1.80 (m, 6H).

Example 4b

Methyl 2-chloro-6-cyclopentylisonicotinate

      2-Cyclopentyl-6-hydroxyisonicotinic acid (147 g, 0.709 mol, 1 eq.) and phosphorous oxychloride (647 mL, 10 eq.) were heated to 115° C. for 4 h. The mixture was concentrated at normal pressure and an external temperature of 130-150° C. At 20° C. DCM (250 mL) was added. The solution was added to MeOH (1000 mL) below 60° C. The mixture was concentrated under reduced pressure at 50° C. DCM (1 L) was added to the residue and the mixture was washed with water (2×500 mL). The org. layer was concentrated to dryness under reduced pressure at 50° C. to obtain a black oil; yield: 181.7 g (107%); purity (LC-MS): 97% a/a. The product was contaminated with trimethyl phosphate.

Example 5

2-Cyclopentyl-6-methoxyisonicotinic acid


      Methyl 2-chloro-6-cyclopentylisonicotinate (40 g, 0.168 mol, 1 eq.) and 5.4 M NaOMe in MeOH (320 mL, 10 eq.) were heated to reflux for 16 h. Water (250 mL) was added carefully at 80° C. external temperature. Methanol was distilled off at 60° C. and reduced pressure (300 mbar). The residue was acidified with 32% HCl (150 mL) and the pH was adjusted to 1. The mixture was extracted with isopropyl acetate (300 mL). The aq. layer was discarded. The org. layer was washed with water (200 mL). The org. solution was concentrated to dryness under reduced pressure at 60° C. to obtain a white solid; yield: 35.25 g (95%). The crude product was crystallized from acetonitrile (170 mL) to obtain a white solid; 31 g (84%); purity (LC-MS): 97.5% a/a.
      LC-MS: tR=1.516 min, [M+1]+=222; 1H NMR (deutero DMSO) δ=13.50 (br s, 1H), 7.25 (s, 1H), 6.98 (s, 1H), 3.88 (s, 3H), 3.18 (m, 1H), 2.01 (m, 2H), 1.72 (m, 6H).

Example 6

Ethyl 4-cyclopentyl-2,4-dioxobutanoate


      A solution of 20% potassium tert-butoxide in THF (595 mL, 1.1 eq.) and THF (400 mL) was cooled to −20° C. A mixture of diethyloxalate (130 g, 1 eq.) and 1-cyclopentylethanone (100 g, 0.891 mol, 1 eq.) was added at a temperature below −18° C. The reaction mixture was stirred at −10° C. for 30 min and then warmed to 15° C. To the mixture was added 2 M HCl (1 L) and TBME (1 L). The org. layer was separated and washed with water (1 L). The org. layer was evaporated to dryness on a rotary evaporator to obtain an oil; yield: 171 g (91%); purity (GC-MS): 97% a/a; GC-MS: tR=2.50 min, [M+1]+=213;1H NMR δ: 14.55 (m, 1H), 6.41 (s, 1H), 4.37 (q, J=7.1 Hz, 2H), 2.91 (m, 1H), 1.79 (m, 8H), 1.40 (t, J=7.1 Hz, 3H).

Example 7

Ethyl 3-cyano-6-cyclopentyl-2-hydroxyisonicotinate


      Triethylamine (112 mL, 1 eq.) and cyanoacetamide (67.9 g, 1 eq.) was heated in ethanol to 65° C. Ethyl 4-cyclopentyl-2,4-dioxobutanoate (171 g, 0.807 mol, 1 eq.) was added to the mixture at 65° C. The mixture was stirred for 3 h at 65° C. The mixture was cooled to 20° C. and filtered. The product was washed with TBME (2×200 mL).
      The product was dried to obtain a yellow solid; yield: 85 g (40%); purity (LC-MS): 97% a/a; LC-MS: tR=1.41 min, [M+1]+=261; 1H NMR (CDCl3) δ: 12.94 (m, 1H), 6.70 (s, 1H), 4.50 (q, J=7.1 Hz, 2H), 3.11 (m, 1H), 2.21 (m, 2H), 1.96 (m, 2H), 1.78 (m, 4H), 1.48 (t, 3H).

REFERENTIAL EXAMPLES


      Original process described by Goldsworthy in J. Chem. Soc. 1934, 377-378.
      According to Goldsworthy the ketonic ester (ethyl 1-acetylcyclopentanecarboxylate) (19.5 g) was refluxed for 24 h with a considerable excess of potash (19 g) in alcohol (150 cc), two-thirds of the alcohol then distilled off, the residue refluxed for 3 h, the bulk of the alcohol finally removed, saturated brine added, and the ketone extracted with ether. The oil obtained from the extract distilled at 150-160°/760 mm and yielded nearly 4 g of a colourless oil, b.p. 153-155°/760 mm, on redistillation. The semicarbazone, prepared from the ketone and a slight excess of equivalent amounts of semicarbazide and sodium acetate in saturated solution, alcohol just sufficient to clear the solution being finally added, rapidly separated; m.p. 145° after recrystallisation from acetone (Found: N, 24.5. C8H15ON3 requires N, 24.8%).
      The process described by Goldsworthy has been reproduced using K2CO3 in the absence (Referential Example 1) and presence (Referential Example 2) of water.

Referential Example 1

      Ethyl 1-acetylcyclopentanecarboxylate (19.5 g, 0.106 mol) was refluxed for 24 h with K2CO3 (19 g, 0.137 mol, Aldrich: 347825) in ethanol (150 mL). GC-MS indicated a conversion to 3% of the desired product. The solvent was removed and the residue was extracted with ether and brine. Evaporation of solvent yielded 28.5 g of a yellow oil. GC-MS indicated ca. 86% a/a starting material, 3% a/a product.

Referential Example 2

      Ethyl 1-acetylcyclopentanecarboxylate (19.5 g, 0.106 mol) was refluxed for 24 h with K2CO3 (19 g, 0.137 mol, Aldrich: 347825) in ethanol (150 mL) in the presence of water (1.91 g, 1 eq.). GC-MS indicated a conversion to 17% of the desired product. The reaction mixture was discarded.

PATENT

US8658675

https://www.google.com/patents/US8658675

Martin Bolli, Cyrille Lescop, Boris Mathys,Keith Morrison, Claus Mueller, Oliver Nayler,Beat Steiner,

novel compounds of Formula (I) that are agonists for the G protein-coupled receptor S1P1/EDG1 and have a powerful and long-lasting immunomodulating effect which is achieved by reducing the number of circulating and infiltrating T- and B-lymphocytes, without affecting their maturation, memory, or expansion. The reduction of circulating T-/B-lymphocytes as a result of S1P1/EDG1 agonism, possibly in combination with the observed improvement of endothelial cell layer function associated with S1P1/EDG1 activation, makes such compounds useful to treat uncontrolled inflammatory diseases and to improve vascular functionality. Prior art document WO 2008/029371 discloses compounds that act as S1P1/EDG1 receptor agonists and show an immunomodulating effect as described above. Unexpectedly, it has been found that the compounds of the present invention have a reduced potential to constrict airway tissue/vessels when compared to compounds of the prior art document WO 2008/029371. The compounds of the present invention therefore demonstrate superiority with respect to their safety profile, e.g. a lower risk of bronchoconstriction.

Examples of WO 2008/029371, which are considered closest prior art analogues are shown in FIG. 1.

Figure US08658675-20140225-C00002
Figure US08658675-20140225-C00003

The data on the constriction of rat trachea rings compiled in Table 1 illustrate the superiority of the compounds of the present invention as compared to compounds of prior art document WO 2008/029371.

For instance, the compounds of Example 1 and 6 of the present invention show a significantly reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 222 and 226 of WO 2008/029371, respectively. Furthermore, the compounds of Example 1 and 6 of the present invention also show a reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 196 and 204 of WO 2008/029371, respectively. These data demonstrate that compounds wherein R1 represents 3-pentyl and R2represents methoxy are superior compared to the closest prior art compounds of WO 2008/029371, i.e. the compounds wherein R1 represents an isobutyl and R2represents methoxy or wherein R1 represents methyl and R2 represents 3-pentyl. Moreover, also the compound of Example 16 of the present invention, wherein R1is 3-methyl-but-1-yl and R2 is methoxy, exhibits a markedly reduced potential to constrict rat trachea rings when compared to its closest analogue prior art Example 226 of WO 2008/029371 wherein R1 is isobutyl and R2 is methoxy.

The unexpected superiority of the compounds of the present invention is also evident from the observation that the compounds of Example 2 and 7 of the present invention show a markedly reduced potential to constrict rat trachea rings when compared to the compounds of prior art Examples 229 and 233 of WO 2008/029371, respectively. This proves that compounds wherein R1 represents cyclopentyl and R2 represents methoxy are superior compared to the closest prior art compounds of WO 2008/029371, i.e. the compounds wherein R1represents methyl and R2 represents cyclopentyl.

Preparation of Intermediates2-Chloro-6-methyl-isonicotinic acid

The title compound and its ethyl ester are commercially available.

2-(1-Ethyl-propyl)-6-methoxy-isonicotinic acid

a) To a solution of 2,6-dichloroisonicotinic acid (200 g, 1.04 mol) in methanol (3 L), 32% aq. NaOH (770 mL) is added. The stirred mixture becomes warm (34° C.) and is then heated to 70° C. for 4 h before it is cooled to rt. The mixture is neutralised by adding 32% aq. HCl (100 mL) and 25% aq. HCl (700 mL). The mixture is stirred at rt overnight. The white precipitate that forms is collected, washed with methanol and dried. The filtrate is evaporated and the residue is suspended in water (200 mL). The resulting mixture is heated to 60° C. Solid material is collected, washed with water and dried. The combined crops give 2-chloro-6-methoxy-isonicotinic acid (183 g) as a white solid; LC-MS: tR=0.80 min, [M+1]+=187.93.

b) To a suspension of 2-chloro-6-methoxy-isonicotinic acid (244 g, 1.30 mol) in methanol (2.5 L), H2SO4 (20 mL) is added. The mixture is stirred at reflux for 24 h before it is cooled to 0° C. The solid material is collected, washed with methanol (200 mL) and water (500 mL) and dried under HV to give 2-chloro-6-methoxy-isonicotinic acid methyl ester (165 g) as a white solid; LC-MS: tR=0.94 min, [M+1]+=201.89.

c) Under argon, Pd(dppf) (3.04 g, 4 mmol) is added to a solution of 2-chloro-6-methoxy-isonicotinic acid methyl ester (50 g, 0.248 mol) in THF (100 mL). A 0.5 M solution of 3-pentylzincbromide in THF (550 mL) is added via dropping funnel. Upon complete addition, the mixture is heated to 85° C. for 18 h before it is cooled to rt. Water (5 mL) is added and the mixture is concentrated. The crude product is purified by filtration over silica gel (350 g) using heptane:EA 7:3 to give 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid methyl ester (53 g) as a pale yellow oil; 1H NMR (CDCl3): δ0.79 (t, J=7.5 Hz, 6H), 1.63-1.81 (m, 4H), 2.47-2.56 (m, 1H), 3.94 (s, 3H), 3.96 (s, 3H), 7.12 (d, J=1.0 Hz, 1H), 7.23 (d, J=1.0 Hz, 1H).

d) A solution of 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid methyl ester (50 g, 0.211 mol) in ethanol (250 mL), water (50 mL) and 32% aq. NaOH (50 mL) is stirred at 80° C. for 1 h. The mixture is concentrated and the residue is dissolved in water (200 mL) and extracted with TBME. The org. phase is separated and washed once with water (200 mL). The TBME phase is discarded. The combined aq. phases are acidified by adding 25% aq. HCl and then extracted with EA (400+200 mL). The combined org. extracts are concentrated. Water (550 mL) is added to the remaining residue. The mixture is heated to 70° C., cooled to rt and the precipitate that forms is collected and dried to give the title compound (40.2 g) as a white solid; LC-MS: tR=0.95 min, [M+1]+=224.04; 1H NMR (D6-DMSO): δ 0.73 (t, J=7.3 Hz, 6H), 1.59-1.72 (m, 4H), 2.52-2.58 (m, 1H), 3.88 (s, 3H), 7.00 (d, J=1.0 Hz, 1H), 7.20 (d, J=1.0 Hz, 1H).

2-Methoxy-6-(3-methyl-butyl)-isonicotinic acid

The title compound is prepared in analogy to 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid; LC-MS: tR=0.94 min, [M+1]+=224.05; 1H NMR (D6-DMSO): δ 0.92 (d, J=5.8 Hz, 6H), 1.54-1.62 (m, 3H), 2.70-2.76 (m, 2H), 3.88 (s, 3H), 6.99 (s, 1H), 7.25 (s, 1H), 13.52 (s).

2-Cyclopentyl-6-methoxy-isonicotinic acid

The title compound is prepared in analogy to 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid; LC-MS: tR=0.93 min, [M+1]+=222.02; 1H NMR (CDCl3): δ 1.68-1.77 (m, 2H), 1.81-1.90 (m, 4H), 2.03-2.12 (m, 2H), 3.15-3.25 (m, 1H), 3.99 (s, 3H), 7.18 (d, J=1.0 Hz, 1H), 7.35 (d, J=0.8 Hz, 1H).

2-Cyclohexyl-6-methoxy-isonicotinic acid

The title compound is prepared in analogy to 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid; LC-MS: tR=0.98 min, [M+1]+=236.01; 1H NMR (D6-DMSO): δ 1.17-1.29 (m, 1H), 1.31-1.43 (m, 2H), 1.44-1.55 (m, 2H), 1.67-1.73 (m, 1H), 1.76-1.83 (m, 2H), 1.84-1.92 (m, 2H), 2.66 (tt, J=11.3, 3.3 Hz, 1H), 3.88 (s, 3H), 7.00 (d, J=1.0 Hz, 1H), 7.23 (d, J=1.0 Hz, 1H).

2-Cyclopentyl-N-hydroxy-6-methoxy-isonicotinamidine

a) A solution of 2-cyclopentyl-6-methoxy-isonicotinic acid methyl ester (3.19 g, 13.6 mmol) in 7 N NH3 in methanol (50 mL) is stirred at 60° C. for 18 h. The solvent is removed in vacuo and the residue is dried under HV to give crude 2-cyclopentyl-6-methoxy-isonicotinamide (3.35 g) as a pale yellow solid; LC-MS**: tR=0.57 min, [M+1]+=221.38.

b) Pyridine (8.86 g, 91.3 mmol) is added to a solution of 2-cyclopentyl-6-methoxy-isonicotinamide (3.35 g, 15.2 mmol) in DCM (100 mL). The mixture is cooled to 0° C. before trifluoroacetic acid anhydride (9.58 g, 45.6 mmol) is added portionwise. The mixture is stirred at 0° C. for 1 h before it is diluted with DCM (100 mL) and washed with sat. aq. NaHCO3 solution (100 mL) and brine (100 mL). The separated org. phase is dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 9:1 to give 2-cyclopentyl-6-methoxy-isonicotinonitrile (2.09 g) as pale yellow oil; LC-MS**: tR=0.80 min, [M+1]+=not detectable; 1H NMR (D6-DMSO): δ 1.61-1.82 (m, 6H), 1.94-2.03 (m, 2H), 3.16 (quint, J=7.8 Hz, 1H), 3.89 (s, 3H), 7.15 (s, 1H), 7.28 (s, 1H).

c) To a solution of 2-cyclopentyl-6-methoxy-isonicotinonitrile (2.09 g, 10.3 mmol) in methanol (100 mL), hydroxylamine hydrochloride (2.15 g, 31.0 mmol) and NaHCO3 (3.04 g, 36.2 mmol) are added. The mixture is stirred at 60° C. for 18 h before it is filtered and the filtrate is concentrated. The residue is dissolved in EA (300 mL) and washed with water (30 mL). The washings are extracted back with EA (4×100 mL) and DCM (4×100 mL). The combined org. extracts are dried over MgSO4, filtered, concentrated and dried under HV to give the title compound (2.74 g) as a white solid; LC-MS**: tR=0.47 min, [M+1]+=236.24; 1H NMR (D6-DMSO): δ 1.61-1.82 (m, 6H), 1.92-2.01 (m, 2H), 3.04-3.13 (m, 1H), 3.84 (s, 3H), 5.90 (s, 2H), 6.86 (s, 1H), 7.13 (s, 1H), 9.91 (s, 1H).

2-Cyclopentyl-6-methoxy-isonicotinic acid hydrazide

a) To a solution of 2-cyclopentyl-6-methoxy-isonicotinic acid (2.00 g, 9.04 mmol), hydrazinecarboxylic acid benzyl ester (1.50 g, 9.04 mmol) and DIPEA (2.34 g, 18.1 mmol) in DCM (40 mL), TBTU (3.19 g, 9.94 mmol) is added. The mixture is stirred at rt for 2 h before it is diluted with EA (250 mL), washed twice with sat. aq. NaHCO3 solution (150 mL) followed by brine (100 mL), dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 4:1 to give N′-(2-cyclopentyl-6-methoxy-pyridine-4-carbonyl)-hydrazinecarboxylic acid benzyl ester (2.74 g) as pale yellow oil; LC-MS**: tR=0.74 min, [M+1]+=369.69; 1H NMR (D6-DMSO): δ 1.62-1.83 (m, 6H), 1.95-2.05 (m, 2H), 3.10-3.21 (m, 1H), 3.88 (s, 3H), 5.13 (s, 2H), 6.97 (s, 1H), 7.23 (s, 1H), 7.28-7.40 (m, 5H), 9.45 (s, 1H), 10.52 (s, 1H).

b) Pd/C (500 mg, 10% Pd) is added to a solution of N′-(2-cyclopentyl-6-methoxy-pyridine-4-carbonyl)-hydrazinecarboxylic acid benzyl ester (2.74 g, 7.42 mmol) in THF (50 mL) and methanol (50 mL). The mixture is stirred at rt under 1 bar of H2 for 25 h. The catalyst is removed by filtration and the filtrate is concentrated and dried under HV to give the title compound (1.58 g) as an off-white solid; LC-MS**: tR=0.51 min, [M+1]+=236.20; 1H NMR (D6-DMSO): δ 1.60-1.82 (m, 6H), 1.94-2.03 (m, 2H), 3.08-3.19 (m, 1H), 3.86 (s, 3H), 4.56 (s br, 2H), 6.93 (d, J=1.0 Hz, 1H), 7.20 (d, J=1.0 Hz, 1H), 9.94 (s, 1H).

3-Ethyl-4-hydroxy-5-methyl-benzonitrile

The title compound is prepared from 3-ethyl-4-hydroxy-5-methyl-benzaldehyde following literature procedures (A. K. Chakraborti, G. Kaur, Tetrahedron 55 (1999) 13265-13268); LC-MS: tR=0.90 min; 1H NMR (CDCl3): δ1.24 (t, J=7.6 Hz, 3H), 2.26 (s, 3H), 2.63 (q, J=7.6 Hz, 2H), 5.19 (s, 1H), 7.30 (s, 2H).

3-Chloro-4-hydroxy-5-methyl-benzonitrile

The title compound is prepared from commercially available 2-chloro-6-methyl-phenol in analogy to literature procedures (see 3-ethyl-4-hydroxy-5-methyl-benzonitrile); LC-MS: tR=0.85 min. 1H NMR (CDCl3): δ2.33 (s, 3H), 6.10 (s, 1H), 7.38 (s, 1H), 7.53 (d, J=1.8 Hz, 1H).

3-Ethyl-4,N-dihydroxy-5-methyl-benzamidine

The title compound is prepared from 3-ethyl-4-hydroxy-5-methyl-benzonitrile or from commercially available 2-ethyl-6-methyl-phenol following literature procedures (G. Trapani, A. Latrofa, M. Franco, C. Altomare, E. Sanna, M. Usala, G. Biggio, G. Liso, J. Med. Chem. 41 (1998) 1846-1854; A. K. Chakraborti, G. Kaur, Tetrahedron 55 (1999) 13265-13268; E. Meyer, A. C. Joussef, H. Gallardo, Synthesis 2003, 899-905); LC-MS: tR=0.55 min; 1H NMR (D6-DMSO): δ 9.25 (s br, 1H), 7.21 (s, 2H), 5.56 (s, 2H), 2.55 (q, J=7.6 Hz, 2H), 2.15 (s, 3H), 1.10 (t, J=7.6 Hz, 3H).

3-Chloro-4,N-dihydroxy-5-methyl-benzamidine

The title compound is prepared from commercially available 2-chloro-6-methyl-phenol in analogy to literature procedures (e.g. B. Roth et al. J. Med. Chem. 31 (1988) 122-129; and literature cited for 3-ethyl-4,N-dihydroxy-5-methyl-benzamidine); 3-chloro-4-hydroxy-5-methyl-benzaldehyde: LC-MS: tR=0.49 min, [M+1]+=201.00; 1H NMR 82.24 (s, 2H), 2.35 (s, 4H), 5.98 (s br, 1H), 7.59 (d, J=1.8 Hz, 1H), 7.73 (d, J=1.8 Hz, 1H), 9.80 (s, 1H); 3-chloro-4,N-dihydroxy-5-methyl-benzamidine: 1H NMR (D6-DMSO): δ 2.21 (s, 3H), 5.72 (s br, 2H), 7.40 (s, 1H), 7.48 (s, 1H), 9.29 (s br, 1H), 9.48 (s br, 1H).

(R)-4-(2,2-Dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-N-hydroxy-5-methyl-benzamidine

a) To a solution of 3-ethyl-4-hydroxy-5-methyl-benzonitrile (2.89 g, 17.9 mmol) in THF (80 mL), (R)-(2,2-dimethyl-[1,3]dioxolan-4-yl)methanol (2.84 g, 21.5 mmol) followed by triphenylphosphine (5.81 g, 21.5 mmol) is added. The mixture is cooled with an ice-bath before DEAD (9.36 g, 21.5 mmol) is added dropwise. The mixture is stirred at rt for 1 h, the solvent is removed in vacuo and the residue is purified by CC on silica gel eluting with heptane:EA 85:15 to give (R)-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-5-methyl-benzonitrile (4.45 g) as a pale yellow oil; LC-MS**: tR=0.75 min, [M+1]+=not detected; 1H NMR (CDCl3): δ1.25 (t, J=7.5 Hz, 3H), 1.44 (s, 3H), 1.49 (s, 3H), 2.34 (s, 3H), 2.65-2.77 (m, 2H), 3.80-3.90 (m, 2H), 3.94-4.00 (m, 1H), 4.21 (t, J=7.3 Hz, 1H), 4.52 (quint, J=5.8 Hz, 1H), 7.35 (s, 1H), 7.38 (s, 1H).

b) To a mixture of (R)-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-5-methyl-benzonitrile (4.45 g, 16.2 mmol) and NaHCO3 (4.75 g, 56.6 mmol) in methanol (30 mL), hydroxylamine hydrochloride (3.37 g, 48.5 mmol) is added. The mixture is stirred at 60° C. for 18 h before it is filtered and the solvent of the filtrate is removed in vacuo. The residue is dissolved in EA and washed with a small amount of water and brine. The org. phase is separated, dried over MgSO4, filtered, concentrated and dried to give the title compound (5.38 g) as a white solid; LC-MS**: tR=0.46 min, [M+1]+=309.23; 1H NMR (D6-DMSO): δ 1.17 (t, J=7.5 Hz, 3H), 1.33 (s, 3H), 1.38 (s, 3H), 2.25 (s, 3H), 2.57-2.69 (m, 2H), 3.73-3.84 (m, 3H), 4.12 (t, J=7.0 Hz, 1H), 4.39-4.45 (m, 1H), 5.76 (s br, 2H), 7.34 (s, 1H), 7.36 (s, 1H), 9.47 (s, 1H).

(R)-3-Chloro-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-N-hydroxy-5-methyl-benzamidine

The title compound is obtained as a colorless oil (1.39 g) in analogy to (R)-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-N-hydroxy-5-methyl-benzamidine starting from 3-chloro-4-hydroxy-5-methyl-benzonitrile and L-α,β-isopropyliden glycerol; LC-MS: tR=0.66 min, [M+H]+=314.96.

(S)-4-(3-Amino-2-hydroxypropoxy)-3-ethyl-5-methylbenzonitrile

a) To a solution of 3-ethyl-4-hydroxy-5-methyl-benzonitrile (5.06 g, 31.4 mmol) in THF (80 mL), PPh3 (9.06 g, 34.5 mmol) and (R)-glycidol (2.29 mL, 34.5 mmol) are added. The mixture is cooled to 0° C. before DEAD in toluene (15.8 mL, 34.5 mmol) is added. The mixture is stirred for 18 h while warming up to rt. The solvent is evaporated and the crude product is purified by CC on silica gel eluting with heptane:EA 7:3 to give 3-ethyl-5-methyl-4-oxiranylmethoxy-benzonitrile (5.85 g) as a yellow oil; LC-MS: tR=0.96 min; [M+42]+=259.08.

b) The above epoxide is dissolved in 7 N NH3 in methanol (250 mL) and the solution is stirred at 65° C. for 18 h. The solvent is evaporated to give crude (S)-4-(3-amino-2-hydroxypropoxy)-3-ethyl-5-methylbenzonitrile (6.23 g) as a yellow oil; LC-MS: tR=0.66 min; [M+1]+=235.11.

N—((S)-3-[2-Ethyl-4-(N-hydroxycarbamimidoyl)-6-methyl-phenoxy]-2-hydroxy-propyl)-2-hydroxy-acetamide

a) To a solution of (S)-4-(3-amino-2-hydroxypropoxy)-3-ethyl-5-methylbenzonitrile (6.23 g, 26.59 mmol) in THF (150 mL), glycolic acid (2.43 g, 31.9 mmol), HOBt (4.31 g, 31.9 mmol), and EDC hydrochloride (6.12 g, 31.9 mmol) are added. The mixture is stirred at rt for 18 h before it is diluted with sat. aq. NaHCO3 and extracted twice with EA. The combined org. extracts are dried over MgSO4, filtered and concentrated. The crude product is purified by CC with DCM containing 8% of methanol to give (S)—N-[3-(4-cyano-2-ethyl-6-methyl-phenoxy)-2-hydroxy-propyl]-2-hydroxy-acetamide (7.03 g) as a yellow oil; LC-MS: tR=0.74 min, [M+1]+=293.10; 1H NMR (CDCl3): δ 1.25 (t, J=7.5 Hz, 3H), 2.32 (s, 3H), 2.69 (q, J=7.5 Hz, 2H), 3.48-3.56 (m, 3H), 3.70-3.90 (m, 3H), 4.19 (s, br, 3H), 7.06 (m, 1H), 7.36 (s, 1H), 7.38 (s, 1H).

b) The above nitrile is converted to the N-hydroxy-benzamidine according to literature procedures (e.g. E. Meyer, A. C. Joussef, H. Gallardo, Synthesis 2003, 899-905); LC-MS: tR=0.51 min, [M+1]+=326.13; 1H NMR (D6-DMSO): δ 1.17 (t, J=7.4 Hz, 3H), 2.24 (s, 3H), 2.62 (q, J=7.4 Hz, 2H), 3.23 (m, 1H), 3.43 (m, 1H), 3.67 (m, 2H), 3.83 (s, 2H), 3.93 (m, 1H), 5.27 (s br, 1H), 5.58 (s br, 1H), 5.70 (s, 2H), 7.34 (s, 1H), 7.36 (s, 1H), 7.67 (m, 1H), 9.46 (s br, 1H).

(S)—N-(3-[2-Chloro-4-(N-hydroxycarbamimidoyl)-6-methyl-phenoxy]-2-hydroxy-propyl)-2-hydroxy-acetamide

The title compound is obtained as a beige wax (1.1 g) in analogy to N—((S)-3-[2-ethyl-4-(N-hydroxycarbamimidoyl)-6-methyl-phenoxy]-2-hydroxy-propyl)-2-hydroxy-acetamide starting from 3-chloro-4-hydroxy-5-methyl-benzonitrile; LC-MS: tR=0.48 min, [M+H]+=331.94.

3-Chloro-N-hydroxy-4-methanesulfonylamino-5-methyl-benzamidine

a) A mixture of 4-amino-3-chloro-5-methylbenzonitrile (155 mg, 930 μmol) and methanesulfonylchloride (2.13 g, 18.6 mmol, 1.44 mL) is heated under microwave conditions to 150° C. for 7 h. The mixture is cooled to rt, diluted with water and extracted with EA. The org. extract is dried over MgSO4, filtered and concentrated. The crude product is purified on prep. TLC using heptane:EA 1:1 to give N-(2-chloro-4-cyano-6-methyl-phenyl)-methanesulfonamide (105 mg) as an orange solid; LC-MS**: tR=0.48 min; 1H NMR (CDCl3): δ2.59 (s, 3H), 3.18 (s, 3H), 6.27 (s, 1H), 7.55 (d, J=1.3 Hz, 1H), 7.65 (d, J=1.5 Hz, 1H).

b) Hydroxylamine hydrochloride (60 mg, 858 μmol) and NaHCO3 (72 mg, 858 μmol) is added to a solution of N-(2-chloro-4-cyano-6-methyl-phenyl)-methanesulfonamide (105 mg, 429 μmol) in methanol (10 mL). The mixture is stirred at 65° C. for 18 h. The solvent is removed in vacuo and the residue is dissolved in a small volume of water (2 mL) and extracted three times with EA (15 mL). The combined org. extracts are dried over MgSO4, filtered, concentrated and dried to give the title compound (118 mg) as a white solid; LC-MS**: tR=0.19 min, [M+1]+=277.94; 1H NMR (CDCl3): δ2.57 (s, 3H), 3.13 (s, 3H), 6.21 (s, 1H), 7.49 (d, J=1.5 Hz, 1H), 7.63 (d, J=1.5 Hz).

3-Ethyl-N-hydroxy-4-methanesulfonylamino-5-methyl-benzamidine

a) In a 2.5 L three-necked round-bottom flask 2-ethyl-6-methyl aniline (250 g, 1.85 mol) is dissolved in DCM (900 mL) and cooled to 5-10° C. Bromine (310.3 g, 1.94 mol) is added over a period of 105 min such as to keep the temperature at 5-15° C. An aq. 32% NaOH solution (275 mL) is added over a period of 10 min to the greenish-grey suspension while keeping the temperature of the reaction mixture below 25° C. DCM (70 mL) and water (100 mL) are added and the phases are separated. The aq. phase is extracted with DCM (250 mL). The combined org. phases are washed with water (300 mL) and concentrated at 50° C. to afford the 4-bromo-2-ethyl-6-methyl-aniline (389 g) as a brown oil; 1H NMR (CDCl3): δ 1.27 (t, J=7.3 Hz, 3H), 2.18 (s, 3H), 2.51 (q, J=7.3 Hz, 2H), 3.61 (s br, 1H), 7.09 (s, 2H).

b) A double-jacketed 4 L-flask is charged with 4-bromo-2-ethyl-6-methyl-aniline (324 g, 1.51 mol), sodium cyanide (100.3 g, 1.97 mol), potassium iodide (50.2 g, 0.302 mol) and copper(I)iodide (28.7 g, 0.151 mol). The flask is evacuated three times and refilled with nitrogen. A solution of N,N′-dimethylethylenediamine (191.5 mL, 1.51 mol) in toluene (750 mL) is added. The mixture is heated to 118° C. and stirred at this temperature for 21 h. The mixture is cooled to 93° C. and water (1250 mL) is added to obtain a solution. Ethyl acetate (1250 mL) is added at 22-45° C. and the layers are separated. The org. phase is washed with 10% aq. citric acid (2×500 mL) and water (500 mL). The separated org. phase is evaporated to dryness to afford 4-amino-3-ethyl-5-methyl-benzonitrile (240 g) as a metallic black solid; 1H NMR (CDCl3): δ1.29 (t, J=7.5 Hz, 3H), 2.19 (s, 3H), 2.52 (q, J=7.3 Hz, 2H), 4.10 (s br, 1H), 7.25 (s, 2H).

c) The title compound is then prepared from the above 4-amino-3-ethyl-5-methyl-benzonitrile in analogy to 3-chloro-N-hydroxy-4-methanesulfonylamino-5-methyl-benzamidine; LC-MS**: tR=0.26 min, [M+1]+=272.32.

3-Chloro-4-ethanesulfonylamino N-hydroxy-5-methyl-benzamidine

The title compound is prepared in analogy to 3-chloro-N-hydroxy-4-methanesulfonylamino-5-methyl-benzamidine using ethanesulfonylchloride; LC-MS**: tR=0.27 min, [M+1]+=292.13; 1H NMR (D6-DMSO): δ 1.36 (t, J=7.5 Hz, 3H), 2.40 (s, 3H), 3.22 (q, J=7.5 Hz), 5.88 (s, 2H), 7.57 (d, J=1.5 Hz, 1H), 7.63 (d, J=1.5 Hz, 1H), 9.18 (s, 1H), 9.78 (s, 1H).

4-Benzyloxy-3-ethyl-5-methyl-benzoic acid

a) To a solution of 3-ethyl-4-hydroxy-5-methyl-benzaldehyde (34.9 g, 0.213 mol, prepared from 2-ethyl-6-methyl-phenol according to the literature cited for 3-ethyl-4,N-dihydroxy-5-methyl-benzamidine) in MeCN (350 mL), K2CO3 (58.7 g, 0.425 mol) and benzylbromide (36.4 g, 0.213 mol) are added. The mixture is stirred at 60° C. for 2 h before it is cooled to rt, diluted with water and extracted twice with EA. The org. extracts are washed with water and concentrated to give crude 4-benzyloxy-3-ethyl-5-methyl-benzaldehyde (45 g) as an orange oil. 1H NMR (CDCl3): δ1.29 (t, J=7.5 Hz, 3H), 2.40 (s, 3H), 2.77 (q, J=7.8 Hz, 2H), 4.90 (s, 2H), 7.31-7.52 (m, 5H), 7.62 (d, J=1.5 Hz, 1H), 7.66 (d, J=1.8 Hz, 1H), 9.94 (s, 1H).
b) To a mixture of 4-benzyloxy-3-ethyl-5-methyl-benzaldehyde (132 g, 0.519 mol) and 2-methyl-2-butene (364 g, 5.19 mol) in tert.-butanol (1500 mL), a solution of NaH2PO4 dihydrate (249 g, 2.08 mol) in water (1500 mL) is added. To this mixture, NaClO2 (187.8 g, 2.08 mol) is added in portions. The temperature of the reaction mixture is kept below 30° C., and evolution of gas is observed. Upon completion of the addition, the orange bi-phasic mixture is stirred well for 3 h before it is diluted with TBME (1500 mL). The org. layer is separated and washed with 20% aq. NaHS solution (1500 mL) and water (500 mL). The org. phase is then extracted three times with 0.5 N aq. NaOH (1000 mL), the aq. phase is acidified with 25% aq. HCl (500 mL) and extracted twice with TBME (1000 mL). These org. extracts are combined and evaporated to dryness to give the title compound; 1H NMR (D6-DMSO): δ 1.17 (t, J=7.5 Hz, 3H), 2.31 (s, 3H), 2.67 (q, J=7.5 Hz, 2H), 4.86 (s, 2H), 7.34-7.53 (m, 5H), 7.68 (s, 2H), 12.70 (s, 1H).

Example 1 (S)-3-(2-Ethyl-4-{5-[2-(1-ethyl-propyl)-6-methoxy-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenoxy)-propane-1,2-diol

a) To a solution of 2-(1-ethyl-propyl)-6-methoxy-isonicotinic acid (190 mg, 732 μmol) in THF (10 mL) and DMF (2 mL), DIPEA (190 mg, 1.46 mmol) followed by TBTU (235 mg, 732 μmol) is added. The mixture is stirred at rt for 10 min before (R)-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-N-hydroxy-5-methyl-benzamidine 226 mg, 732 μmol) is added. The mixture is stirred at rt for 1 h before it is diluted with EA and washed with water. The org. phase is separated and concentrated. The remaining residue is dissolved in dioxane (10 mL) and heated to 105° C. for 18 h. The mixture is cooled to rt, concentrated and the crude product is purified on prep. TLC plates using DCM containing 10% of methanol to give 4-{3-[4-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-5-methyl-phenyl]-[1,2,4]oxadiazol-5-yl}-2-(1-ethyl-propyl)-6-methoxy-pyridine (256 mg) as a yellow oil; LC-MS: tR=1.28 min, [M+H]+=496.23.

b) A solution of 4-{3-[4-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3-ethyl-5-methyl-phenyl]-[1,2,4]oxadiazol-5-yl}-2-(1-ethyl-propyl)-6-methoxy-pyridine (250 mg, 504 μmol) in 4 M HCl in dioxane (10 mL) is stirred at rt for 90 min before it is concentrated. The crude product is purified on prep. TLC plates using DCM containing 10% of methanol to give the title compound (76 mg) as a pale brownish solid; LC-MS: tR=1.12 min, [M+H]+=456.12; 1H NMR (CDCl3): δ0.85 (t, J=7.0 Hz, 6H), 1.33 (t, J=7.0 Hz, 3H), 1.70-1.89 (m, 4H), 2.42 (s, 3H), 2.61-2.71 (m, 1H), 2.78 (q, J=7.3 Hz, 2H), 3.82-4.00 (m, 4H), 4.04 (s, 3H), 4.14-4.21 (m, 1H), 7.34 (s, 1H), 7.46 (s, 1H), 7.86-7.91 (m, 2H).

Example 2 (S)-3-{4-[5-(2-Cyclopentyl-6-methoxy-pyridin-4-yl)-[1,2,4]oxadiazol-3-yl]-2-ethyl-6-methyl-phenoxy}-propane-1,2-diol

The title compound is prepared in analogy to Example 1 starting from 2-cyclopentyl-6-methoxy-isonicotinic acid; LC-MS: tR=1.14 min, [M+H]+=454.16; 1H NMR (CDCl3): δ1.33 (t, J=7.5 Hz, 3H), 1.72-1.78 (m, 2H), 1.85-1.94 (m, 4H), 2.03-2.15 (m, 2H), 2.41 (s, 3H), 2.72 (d, J=5.3 Hz, 1H), 2.77 (q, J=7.5 Hz, 2H), 3.19-3.28 (m, 1H), 3.81-3.94 (m, 2 H), 3.95-3.98 (m, 2H), 4.02 (s, 3H), 4.14-4.21 (m, 1H), 7.31 (d, J=1.3 Hz, 1H), 7.51 (d, J=1.0 Hz, 1H), 7.88 (d, J=1.8 Hz), 7.89 (d, J=2.0 Hz, 1H).

PAPER

Abstract Image

A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether derived from enantiomerically pure (R)-isopropylidene glycerol ((R)-solketal) and 3-ethyl-4-hydroxy-5-methylbenzonitrile in 71% yield in a one-pot reaction. The overall sequence entails 18 chemical steps with 10 isolated intermediates. All raw materials are cheap and readily available in bulk quantities, the reaction conditions match with standard pilot plant equipment, and the route reproducibly afforded 3–20 kg of 1 in excellent purity and yield for clinical studies.

Practical Synthesis of a S1P Receptor 1 Agonist via a Guareschi–Thorpe Reaction

Chemistry Process R&D, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.6b00210
*E-mail: stefan.abele@actelion.com. Telephone: +41 61 565 67 59.
 (1H NMR): 99.40% w/w; er (HPLC method 2): (S):(R) = 99.7:0.3, tR 10.70 min (S-isomer), 14.5 min (R-isomer);
mp 80 °C (DSC);
1H NMR (d6-DMSO): δ 7.78 (s, 2 H), 7.53 (s, 1 H), 7.26 (s, 1 H), 4.98 (d, J = 4.6 Hz, 1 H), 4.65 (s, 1 H), 3.94 (s, 3 H), 3.86 (m, 2 H), 3.75 (m, 1 H), 3.50 (t, J = 5.4 Hz, 2 H), 3.28 (m, 1 H), 2.75 (d, J = 7.5 Hz, 2 H), 2.35 (s, 3 H), 2.03 (m, 2 H), 1.81 (m, 4 H), 1.69 (m, 2 H), 1.22 (t, J = 7.5 Hz, 3 H).
13C NMR (CDCl3): δ 174.3, 168.9, 165.8, 164.4, 157.4, 137.7, 133.6, 131.7, 128.4, 126.7, 122.5, 112.0, 106.0, 73.9, 71.1, 63.8, 53.7, 47.5, 33.3, 25.9, 22.9, 16.4, 14.8.
Patent ID Date Patent Title
US2015133669 2015-05-14 NEW PROCESS FOR THE PREPARATION OF 2-CYCLOPENTYL-6-METHOXY-ISONICOTINIC ACID
US8658675 2014-02-25 Pyridin-4-yl derivatives
//////////ACT-334441, ACT 334441, ACT334441, CENERIMOD, S1P receptor 1 agonist, Systemic lupus erythematosus, UNII-Y333RS1786  Y333RS1786, phase 2, Actelion Pharmaceuticals Ltd.Martin Bolli, Cyrille Lescop, Boris Mathys,Keith Morrison, Claus Mueller, Oliver Nayler,Beat Steiner,
OC[C@H](O)COC1=C(C)C=C(C2=NOC(C3=CC(C4CCCC4)=NC(OC)=C3)=N2)C=C1CC

Is AQL Testing required within the 100% Visual Inspection?


DRUG REGULATORY AFFAIRS INTERNATIONAL

Is AQL Testing required within the 100% Visual Inspection?
One of the most frequently asked questions is whether an additional testing based on samples is required after the 100% visual inspection of parenterals. The answer is: basically, “yes”.

http://www.gmp-compliance.org/enews_05496_Two-new-FDA-Warning-Letters-for-API-Manufacturers-in-China_15488,15484,Z-QCM_n.html

One of the most frequently asked questions is whether an additional AQL testing based on samples is required after the 100% visual inspection of parenterals. The background for that question is the probabilistic nature of visual inspection. It is known that the discovery of defects (like for example particulates) is a matter of detection probability. In other words, visual inspection cannot exclude that defective containers may still be in the batch which hasn’t been sorted out. This applies to manual, semi-automatic and also automatic visual inspection.

The American Pharmacopoeia has reacted to that and has integrated AQL testing in the monograph Visible Particulates in Injections. Here, the value 0.65 has been…

View original post 203 more words

Two new FDA Warning Letters for API Manufacturers in China


DRUG REGULATORY AFFAIRS INTERNATIONAL

Two new FDA Warning Letters for API Manufacturers in China

In June 2016, two API manufacturers in China received a Warning Letter from the FDA. Both companies had major deficiencies regarding data integrity. For instance, manipulations were found in HPLC analyses as well as in GC analyses. You will find more information on the current FDA Warning Letters for Chongqing Lummy and Shanghai Desano here. http://www.gmp-compliance.org/enews_05496_Two-new-FDA-Warning-Letters-for-API-Manufacturers-in-China_15488,15484,Z-QCM_n.html
The Chinese Company Chongqing Lummy Pharmaceutical Co., Ltd. received a Warning Letter from the FDA on June 21, 2016. This Warning Letter referred to both the FDA inspection from March 14-16, 2016 and the response which the API manufacturer had sent to the FDA on March 31, 2016.

It was claimed that Chongqing Lummy Pharmaceuticals had no adequate control in place to prevent data manipulation or deletion. The FDA investigator’s review of the audit trail revealed that an analyst had manipulated the computerized gas…

View original post 425 more words

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