FLAGS AND HITS
DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO
FACEBOOK
...................................................................Join me on twitter
..................................................................Join me on google plus
GoogleplusMYSELF
PALINAVIR
PALINAVIR, BILA-2011-BS
| Patent | Submitted | Granted |
|---|---|---|
| Substituted pipecolinic acid derivatives as HIV protease inhibitors [US5614533] | 1997-03-25 | |
| Substituted pipecolinic acid derivatives as HIV protease inhibitors. [EP0560268] | 1993-09-15 | 1995-01-04 |
……………………….
PATENT
http://www.google.com/patents/WO2013105118A1?cl=en
Scheme 5: Synthesis of Palinavir (6):
The organic solvent mentioned according to the invention is selected from the group consisting of organic solvents, wherein the organic solvents are polar aprotic such as DCM, THF, Ethyl acetate, acetone, DMF, acetonitrile, DMSO ; polar protic solvents such as lower alcohol particularly (C1-C6) alkyl alcohol, water, acetic acid ; non-polar solvents such as hexane, benzene, toluene, chloroform, pet. ether, 1,4-dioxane, heptane either alone or mixtures thereof . Additionally the purification or separation of crude product can be accomplished by known techniques viz. extraction, column chromatography in a suitable organic solvent with the aid of instruments such as TLC, HPLC, GC, mass spectroscopy, or distillation, crystallization, derivatization.
Want to know everything on vir series
click
http://drugsynthesisint.blogspot.in/p/vir-series-hep-c-virus-22.html
AND
http://medcheminternational.blogspot.in/p/vir-series-hep-c-virus.html
………………………….
J Org Chem 1997,62(11),3440
The reaction of tert-butoxycarbonyl-L-phenylalanine (I) with isobutyl chloroformate in THF gives the expected mixed anhydride which is treated with diazomethane and HCl yielding the corresponding chloromethyl ketone (II). The reduction of (II) with NaBH4 in THF affords the (S)-chlorohydrin (IV), which is treated with KOH in ethanol to obtain the chiral epoxide (V)(1,2). Ring opening of (V) with (?(cis)-N-tert-butyl-4-(4-pyridylmethoxy)piperidine-2-carboxamide (VI) by a treatment with LiCl in refluxing ethanol gives a mixture of diastereomers that is separated by chromatography giving the pure isomer (VII). The reaction of (VII) with tert-butoxycarbonyl-L-valine (VIII) by treatment first with trifluoroacetic acid (TFA), and condesation by means of BOP ((benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate) and NMM (N-methylmorpholine) affords the expected condensation product (IX). Finally, this compound is condensed with quinoline-2-carboxylic acid (X) by means of BOP and NMM as before. 2) The piperidine (VI) has been obtained by condensation of (?(cis)-N-(tert-butoxycarbonyl)-4-hydroxypiperidine-2-carboxamide (XI) with 4-(chloromethyl)pyridine (XII) by means of NaH in DMS, followed by hydrolysis with HCl.
Palinavir can also be obtained as follows: The controlled oxidation of 2(S)-(dibenzylamino)-3-phenyl-1-propanol (XIII) with pyridine-SO3 complex in DMSO gives the corresponding aldehyde (XIV), which is condensed with bromochloromethane (XV) by means of Li in THF followed by hydrolysis with HCl yielding regioselectively the 1-chloro-2-butanol (XVI). The debenzylation of (XVI) by hydrogenation over Pd/C affords the free amine (XVII), which is treated with tert-butoxycarbonyl anhydride/triethylamine and dehydrochlorinated with KOH in methanol to give the desired chiral epoxide (V).
The chiral piperidine (2S,4R)(VI) has been obtained as follows: The cyclization of 3-buten-1-ol (XXII) with (S)-1-phenylethylamine (XXIII) and glyoxylic acid (XXIV) by means of tosyl chloride in THF gives a mixture of the (2S,4R) and (2R,4S) lactones (XXV), which is resolved by fractional crystallyzation of their salts with the chiral camphorsulfonic acid (XXVI), followed by elimination of the acid with ammonia to afford (2S,4R)(XXVII). The reaction of lactone (XXVII) with isopropylmagnesium chloride and tert-butylamine in THF gives (2S,4R)-N-tert-butyl-4-hydroxy-1-(1(S)-phenylethyl)piperidine-2-carboxamide (XXVIII), which is debenzylated by hydrogenation and protected with tert-butoxycarbonyl anhydride yielding (2S,4R)-N-(tert-butoxycarbonyl)-4-hydroxypiperidine-2-carboxamide (2S,4R)(XI), which is finally condensed with 4-(chloromethyl)pyridine (XII) as before to obtain the chiral piperidine (2S,4R)(VI), already reported.
The condendsation of epoxide (V) with (2S,4R)(VI) by means of basic alumina in THF, followed by elimination of the protecting group with HCl and NaOH yields directly the condensation product (XVIII) as a pure diastereomer and with a free amino group. Finally, this compound is condensed with N-(2-quinolylcarbonyl)-L-valine (XIX) through its activation compound with isobutyl chloroformate (the 4(S)-isopropyl-2-(2-quinolyl)oxazol-5(4H)-one (XX)). The N-acyl-L-valine (XIX) has been obtained by acylation of L-valine (XXI) with quinoline-2-carboxylic acid (X) through its acyl chloride obtained with SOCl2.
………………………..
Palinavir is an inhibitor with five chiral centers. It contains the amino acid valine and pipecolinin acid. The previous way to create this drug faced three major obstacles. First, the reaction from 2 to 3 used diazomethane. Therefore, is is difficult, if not impossible, to produce large quantities. Secondly, the steps included in going from 4 to 5 gave way to racemers which is very inefficient. Finally, chromatography is needed at two separate times.
Four issues were addresses in route to product 1. First, because of the number of chiral centers, stereochemical control was a concern. high chemical yields were a second concern. Also, multi step procedures were advantageous to cut down on purification steps. Finally, the synthesis tried to restrict the use of hazardous reagents. The following retrosynthesis reaction was conceived and three target molecules were identified as seen in figure 1.
Molecule 3 uses a diaseteroselective addition of in situ (chloromethyl)lithium to N,N-dibenzylphenylalaninol and is derived from a four step process.
Recrystallization of 13 is required. Molecule 14 was not reached because it posed a problem later in the reaction. The N-benzyl protection group could not be removed to react with 9.
8 is a derivative of naturally occurring pipocolic acid, 16, named 3-buten-1-ol. Selective crystallization of diastereomeric salts can lead to 17a, but a more efficient way is by having a 60:40 mixture of lactones 17a,b. This leads to 18a,b using a Brodroux process. Crystallization of 18a,b lead to a poor overall yield. Instead, 18a,b undergoes salt crystallization with (-)-camphorsulfonic acid. Finally, 18a underwent hydrolysis and then addition of di-tert butyl dicarbonate leads to 8.
8 was then transformed to 5 in a three step process.
8 was added to NaOH and alkylated with 4-picolyl chloride. The protecting group was lost with the addition of acid.
Derivation of 9 was started by a simple substitution of 19, quinoline-2-carboxylic acid, to 20, an acid chloride, with the help of thionyl chloride. Acylation of amino acid L-valine to 20 was accomplished by a biphasic system.
In the original synthesis of palinavir, a 2:1 mixture of 3 to 5 was needed to produce only ~35% of 6 and flash chromatography was needed. On a large scale without chromatography, 6 was produced with a 85% yield, but 21 was also produced. To keep the production of 21 to a minimum, the reaction was performed in a solution that was degassed. This insured that the pyridine ring would not react in the presence of air. With this precaution, only 1-2% of the yield was 21. A washing of the solution with 1 M KH2PO4 removed and left over 5. Deprotection was achieved with the addition of concentrated HCl and followed by adding NaOH. The product of 10 was a “viscous syrup”. 22 was 1-1.5% of the product and was not removed before the addition of 9 to form 80-85% palinavir.
Coupling of 10 and 9 is the final step in the synthesis , although there are still some purification steps left.
Two recrystallizations were required for the final 99.6% purity.
………………………..
Palinavir is a potent peptidomimetic-based HIV protease inhibitor. We have developed a highly convergent and stereoselective synthesis which is amenable to the preparation of multikilogram quantities of this compound. The synthetic sequence proceeds in 24 distinct chemical steps (with several integrated, multistep operations) from commercially available starting materials. No chromatographies are required throughout the process, and the final product is purified by crystallization of its dihydrochloride salt to >99% homogeneity.
crude palinavir (1) as a thick brown oil (yield not determined). HPLC analysis (Supelcosil LZ-ABZ, 10−50% 1% TFA in MeCN/1% TFA in 25 min, 1 mL/min flow rate): 1, tR 17.80 min (84.1%); 24, tR 18.47 min (2.0%); 25, tR 19.97 min (1.45%).
palinavir dihydrochloride (1750 g, 51% yield) containing 0.25% w/w isopropanol (by 1H NMR):
mp 175−185 °C.
[α]25D −13.0° (c 1, MeOH). [α]25Hg365 +44.9° (c 1, MeOH).
IR (KBr) ν 3700−2300, 1660, 1555, 1520 cm-1.
1H NMR (DMSO-d6) δ 10.00 (broad s, 1H), 8.88 (d, J = 6.3 Hz, 2H), 8.61 (d, J = 8.4 Hz, 1H), 8.60 (s, 1H), 8.51 (d, J = 9.6 Hz, 1H), 8.35 (d, J = 8.7 Hz, 1H), 8.20 (d, J = 8.4 Hz, 1H), 8.16 (d, J = 8.7 Hz, 1H), 8.11 (d, J = 8.1 Hz, 1H), 7.94 (d, J = 6.0 Hz, 2H), 7.89 (t, J = 7.6 Hz, 1H), 7.74 (t, J = 7.5 Hz, 1H), 7.19 (d, J = 7.2 Hz, 2H), 7.08 (t, J = 7.5 Hz, 2H), 6.91 (t, J = 7.3 Hz, 1H), 4.86 (AB quartet, 2H), 4.37 (broad t, J = 7.8 Hz, 1H), 4.21 (d, J = 11.4 Hz, 1H), 4.11 (broad m, 1H), 3.96 (broad m, 1H), 3.80−3.65 (m, 2H), 3.26 (t, J = 7.4 Hz, 1H), 3.15−3.01 (m, 2H), 2.94 (broad d, J = 12.0 Hz, 1H), 2.62 (dd, J = 13.6, 10.6 Hz, 1H), 2.56 ((broad d, J = 12.0 Hz, 1H), 2.20−2.05 (m, 2H), 1.86 (m, 1H), 1.69 (q, J = 11.7 Hz, 1H), 1.31 (s, 9H), 0.81 (d, J = 6.3 Hz, 3H), 0.80 (d, J = 6.6 Hz, 3H).
13C NMR (DMSO-d6) δ 170.4, 166.4, 163.3, 158.3, 149.5, 145.9, 141.9, 138.6, 138.2, 130.7, 129.3, 129.1, 129.0, 128.3, 128.2, 128.0, 125.9, 124.1, 118.6, 72.3, 68.8, 67.2, 64.8, 58.0, 57.8, 54.4, 51.3, 51.1, 35.4, 34.1, 31.1, 28.2, 19.5, 17.9.
FAB-MS m/z 709 (MH+ of free base). Anal. Calcd for C41H54Cl2N6O5 (corrected for 8% water content as determined by Karl Fisher analysis and 0.25% w/w isopropanol as determined by 1H NMR): C, 58.31; H, 7.29; N, 9.93. Found: C, 57.76; H, 7.25; N, 9.89. Titration of HCl content using NaOH: 2.09 ± 0.03 mol HCl. HPLC homogeneity (Supelcosil LC-ABZ, 10−50% 1% TFA in MeCN/1% TFA in 25 min, 1 mL/min flow rate): palinavir dihydrochloride, tR 18.24 min (99.51%); 25 tR 20.39 min (0.33%). HPLC homogeneity (Nova-Pak C8, 20−80% MeCN/50 mM NaH2PO4 in 25 min, 1 mL/min flow rate): palinavir dihydrochloride, tR 15.52 min (99.67%); 25 tR 13.52 min (0.33%).
PURE palinavir (1) as a white amorphous powder (1902 g, 84% yield):
mp 100−107 °C. [α]25D −11.5° (c 1, MeOH).
IR (KBr) ν 3700−3100, 1660, 1520, 1495 cm-1.
1H NMR (CDCl3) δ 8.54 (d, J = 5.7 Hz, 2H), 8.48 (d, J = 8.6 Hz, 1H), 8.31 (d, J = 8.6 Hz, 1H, part of AB), 8.22 (d, J = 8.3 Hz, 1H, part of AB), 8.13 (d, J = 8.3 Hz, 1H), 7.90 (d, J = 8.0 Hz, 1H), 7.80 (t, J = 7.6 Hz, 1H), 7.65 (t, J = 7.6 Hz, 1H), 7.25 (d, J = 5.4 Hz, 2H), 7.13 (d, J = 7.3 Hz, 2H), 7.07 (t, J = 7.5 Hz, 1H), 6.92 (t, J = 7.3 Hz, 1H), 6.59 (d, J = 8.3 Hz, 1H), 6.57 (s, 1H), 4.61 (d, J = 13.4 Hz, 1H, part of AB), 4.51 (d, J = 13.4 Hz, 1H, part of AB), 4.32 (dd, J = 8.6, 6.4 Hz, 1H), 4.22 (m, 1H), 3.97 (m, 1), 3.47−3.33 (m, 2H), 2.94 (dd, J = 14.3, 4.1 Hz, 1H), 2.89 (d, J= 8.6 Hz, 1H), 2.79−2.72 (m, 1H), 2.77 (dd, J = 14.3, 10.8 Hz, 1H), 2.43 (dd, J = 13.4, 8.3 Hz, 1H), 2.40−2.25 (m, 3H), 1.95 (broad d, J = 12.4 Hz, 1H), 1.65 (q J = 11.8 Hz, 2H), 1.32 (s, 9H), 0.95 (d, J = 7.0 Hz, 3H), 0.83 (d, J = 6.7 Hz, 3H).
13C NMR (CDCl3) δ 171.6, 171.2, 165.0, 149.8, 148.8, 147.9, 146.5, 137.6, 137.5, 130.3, 129.9, 129.5, 129.4, 129.0, 128.8, 128.5, 128.2, 127.7, 126.4, 121.7, 118.8, 75.0, 71.9, 68.1, 66.7, 59.4, 56.9, 54.6, 50.9, 50.2, 34.8, 33.3, 29.8, 29.7, 28.7, 19.6, 17.5.
FAB-MS m/z 709 (MH+). Anal. Calcd for C41H52N6O5(corrected for 0.7% water content as determined by Karl Fisher analysis): C, 68.98; H, 7.42; N, 11.77. Found: C, 68.71; H, 7.47; N, 11.71. HPLC homogeneity (Supelcosil LC-ABZ, 10−50% 1% TFA in MeCN/1% TFA in 25 min, 1 mL/min flow rate): palinavir (1), tR 17.83 min (99.59%); 25 tR20.00 min (0.41%). HPLC homogeneity (Nova-Pak C8, 10−80% MeCN/50 mM NaH2PO4 in 25 min, 1 mL/min flow rate): palinavir (1), tR 17.37 min (99.51%); 25 tR 15.87 min (0.49%).
| Reference | ||
|---|---|---|
| 1 | * | ARUN K. GHOSH ET AL: “The Development of Cyclic Sulfolanes as Novel and High-Affinity P2 Ligands for HIV-1 Protease Inhibitors“, JOURNAL OF MEDICINAL CHEMISTRY, vol. 37, no. 8, 1 April 1994 (1994-04-01), pages 1177-1188, XP055057710, ISSN: 0022-2623, DOI: 10.1021/jm00034a016 |
| 2 | * | KAY BRICKMANN ET AL: “Synthesis of Conformationally Restricted Mimetics of [gamma]-Turns and Incorporation into Desmopressin, an Analogue of the Peptide Hormone Vasopressin“, CHEMISTRY – A EUROPEAN JOURNAL, vol. 5, no. 8, 2 August 1999 (1999-08-02), pages 2241-2253, XP055057517, ISSN: 0947-6539, DOI: 10.1002/(SICI)1521-3765(19990802)5:8<2241: :AID-CHEM2241>3.0.CO;2-L |
| 3 | * | KIRAN I N C ET AL: “A concise enantioselective synthesis of (+)-goniodiol and (+)-8-methoxygoniodiol via Co-catalyzed HKR of anti-(2SR, 3RS)-3-methoxy-3-phenyl-1, 2-epoxypropane“, TETRAHEDRON LETTERS, ELSEVIER, AMSTERDAM, NL, vol. 52, no. 3, 19 January 2011 (2011-01-19), pages 438-440, XP027558447, ISSN: 0040-4039 [retrieved on 2010-12-14] |
| 4 | * | M. TOKUNAGA: “Asymmetric Catalysis with Water: Efficient Kinetic Resolution of Terminal Epoxides by Means of Catalytic Hydrolysis“, SCIENCE, vol. 277, no. 5328, 15 August 1997 (1997-08-15), pages 936-938, XP055057541, ISSN: 0036-8075, DOI: 10.1126/science.277.5328.936 |
| 5 | * | PARKES K E B ET AL: “STUDIES TOWARD THE LARGE-SCALE SYNTHESIS OF THE HIV PROTEINASE INHIBITOR RO 31-8959“, JOURNAL OF ORGANIC CHEMISTRY, ACS, US, vol. 59, no. 13/16, 1 January 1994 (1994-01-01), pages 3656-3664, XP002011975, ISSN: 0022-3263, DOI: 10.1021/JO00092A026 |
| 6 | * | R. SANTHOSH REDDY ET AL: “Co(iii)(salen)-catalyzed HKR of two stereocentered alkoxy- and azido epoxides: a concise enantioselective synthesis of (S,S)-reboxetine and (+)-epi-cytoxazone“, CHEMICAL COMMUNICATIONS, vol. 46, no. 27, 1 January 2010 (2010-01-01), page 5012, XP055057537, ISSN: 1359-7345, DOI: 10.1039/c0cc00650e |
| 7 | * | SHINJI NAGUMO ET AL: “Intramolecular Friedel-Crafts type reaction of vinyloxiranes linked to an ester group“, TETRAHEDRON, vol. 65, no. 47, 1 November 2009 (2009-11-01), pages 9884-9896, XP055057655, ISSN: 0040-4020, DOI: 10.1016/j.tet.2009.09.037 |
| 8 | * | SUNITA K. GADAKH ET AL: “Enantioselective synthesis of HIV protease inhibitor amprenavir via Co-catalyzed HKR of 2-(1-azido-2-phenylethyl)oxirane“, TETRAHEDRON: ASYMMETRY, vol. 23, no. 11-12, 1 June 2012 (2012-06-01), pages 898-903, XP055057475, ISSN: 0957-4166, DOI: 10.1016/j.tetasy.2012.06.003
Want to know everything on vir series click http://drugsynthesisint.blogspot.in/p/vir-series-hep-c-virus-22.html AND http://medcheminternational.blogspot.in/p/vir-series-hep-c-virus.html |
AMPRENAVIR For the treatment of HIV-1 infection in combination with other antiretroviral agents.
Amprenavir
KVX-478, 141W94, VX-478,
(3S)-Tetrahydro-3-furanyl ((1S,2R)-3-(((4-aminophenyl)sulfonyl)(2-methylpropyl)amino)-2-hydroxy-1-(phenylmethyl)propyl)carbamate
(3S)-tetrahydro-3-furyl N-[(1S,2R)-3-(4-amino-N-isobutylbenzenesulphonamido)-1-benzyl-2-hydroxypropyl] carbamate
CAS NO. 161814-49-9, [(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-hydroxy-1-phenylbutan-2-yl]carbamate
| 161814-49-9 | |
| Weight | 505.224656557 |
|---|---|
| Chemical Formula | C25H35N3O6S |
| Amprenavir is a protease inhibitor used to treat HIV infection. |
Amprenavir (Agenerase, GlaxoSmithKline) is a protease inhibitor used to treat HIV infection. It was approved by the Food and Drug Administration on April 15, 1999, for twice-a-day dosing instead of needing to be taken every eight hours. The convenient dosing came at a price, as the dose required is 1,200 mg, delivered in eight very large gel capsules.
Production of amprenavir was discontinued by the manufacturer December 31, 2004; a prodrug version (fosamprenavir) is available.
| Amprenavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Amprenavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs. |
| Country | Patent Number | Approved | Expires (estimated) |
|---|---|---|---|
| United States | 5585397 | 1993-12-17 | 2013-12-17 |
| United States | 6730679 | 1997-11-11 | 2017-11-11 |
Background
Research aimed at development of renin inhibitors as potential antihypertensive agents had led to the discovery of compounds that blocked the action of this peptide cleaving enzyme. The amino acid sequence cleaved by renin was found to be fortuitously the same as that required to produce the HIV peptide coat. Structure–activity studies on renin inhibitors proved to be of great value for developing HIV protease inhibitors. Incorporation of an amino alcohol moiety proved crucial to inhibitory activity for many of these agents. This unit is closely related to the one found in the statine, an unusual amino acid that forms part of the pepstatin, a fermentation product that inhibits protease enzymes.
Synthesis
R.D. Tung, M.A. Murcko, G.R. Bhisetti, U.S. Patent 5,558,397 (1996). The scheme shown here is partly based on that used to prepare darunavir and fosamprenavir due to difficulty in deciphering the patent.
AGENERASE (amprenavir) is an inhibitor of the human immunodeficiency virus (HIV) protease. The chemical name of amprenavir is (3S)-tetrahydro-3-furyl N-[(1S,2R)-3-(4-amino-N-isobutylbenzenesulfonamido)-1-benzyl-2-hydroxypropyl]carbamate. Amprenavir is a single stereoisomer with the (3S)(1S,2R) configuration. It has a molecular formula of C25H35N3O6S and a molecular weight of 505.64. It has the following structural formula:
 |
Amprenavir is a white to cream-colored solid with a solubility of approximately 0.04 mg/mL in water at 25°C.
AGENERASE Capsules (amprenavir capsules) are available for oral administration. Each 50- mg capsule contains the inactive ingredients d-alpha tocopheryl polyethylene glycol 1000 succinate (TPGS), polyethylene glycol 400 (PEG 400) 246.7 mg, and propylene glycol 19 mg. The capsule shell contains the inactive ingredients d-sorbitol and sorbitans solution, gelatin, glycerin, and titanium dioxide. The soft gelatin capsules are printed with edible red ink. Each 50- mg AGENERASE Capsule contains 36.3 IU vitamin E in the form of TPGS. The total amount of vitamin E in the recommended daily adult dose of AGENERASE is 1,744 IU.
………………………………
paper
DOI: 10.1039/B404071F
http://pubs.rsc.org/en/content/articlelanding/2004/ob/b404071f#!divAbstract
Efficient and industrially applicable synthetic processes for precursors of HIV protease inhibitors (Amprenavir, Fosamprenavir) are described. These involve a novel and economical method for the preparation of a key intermediate, (3S)-hydroxytetrahydrofuran, from L-malic acid. Three new approaches to the assembly of Amprenavir are also discussed. Of these, a synthetic route in which an (S)-tetrahydrofuranyloxy carbonyl is attached to L-phenylalanine appears to be the most promising manufacturing process, in that it offers satisfactory stereoselectivity in fewer steps.
Want to know everything on vir series
click
http://drugsynthesisint.blogspot.in/p/vir-series-hep-c-virus-22.html
AND
http://medcheminternational.blogspot.in/p/vir-series-hep-c-virus.html
……………
The reaction of N,N-dibenzyl-L-alaninal (I) with nitromethane, catalyzed by the chiral ammonium salt (II) and KF in THF gives the chiral nitroalcohol (III), which is reduced with NiCl2 and NaBH4 to yield the aminoalcohol (IV). The condensation of (IV) with isobutyraldehyde (V) affords the Schiff base (VI), which is reduced with NaBH4 to provide the secondary amine (VII). The reaction of (VII) with 4-nitrobenzenesulfonyl chloride (VIII) and TEA in dichloromethane furnishes the sulfonamide (IX), which is deprotected by hydrogenation with H2 over Pd/C in methanol, giving the diamino compound (X). Finally, this compound is condensed with 3(S)-tetrahydrofuryl (N-oxysuccinimidyl) carbonate (XI) by means of TEA in dichloromethane to afford the target carbamate.
Angew Chem. Int Ed Engl1999,38,(13-14):1931
……………………………………………………….
The reaction of the chiral epoxide (I) with isobutylamine (II) in refluxing ethanol gives the secondary amine (III), which is protected with benzyl chloroformate (IV) and TEA, yielding the dicarbamate (V). Selective deprotection of (V) with dry HCl in ethyl acetate affords the primary amine (VI), which is treated with 3(S)-tetrahydrofuryl N-succinimidinyl carbonate (VII) (prepared by condensation of tetrahydrofuran-3(S)-ol (VIII) with phosgene and N-hydroxysuccinimide (IX)) and DIEA in acetonitrile to provide the corresponding carbamate (X). The deprotection of (X) by hydrogenation with H2 over Pd/C in ethanol gives the secondary amine (XI), which is condensed with 4-nitrophenylsulfonyl chloride (XII) by means of NaHCO3 in dichloromethane/water to yield the sulfonamide (XIII). Finally, the nitro group of (XIII) is reduced with H2 over Pd/C in ethyl acetate to afford the target compound.
https://www.google.com/patents/WO1999048885A1?cl=ensynthesis of (3S)-tetrahydro-3-furyl N-[(1S,2R)-3(4-amino-N-isobutylbenzenesulphonamido)-1-benzyl-2-hydroxypropyl]carbamate, hereinafter referred to as the compound of formula (I), and to novel intermediates thereto.The compound of formula (I) has the following structure
and was first described in PCT patent publication number WO94/05639 at Example 168. Currently there is considerable interest in the compound of formula (I) as a new chemotherapeutic compound in the treatment of human immunodeficiency virus (HIV) infection and the associated conditions such as acquired immune deficiency syndrome (AIDS) and AIDS dementia.
There exists at the present time a need to produce large quantities of the compound of formula (I) for clinical investigation into the efficacy and safety of the compound as a chemotherapeutic agent in the treatment of HIV infections.
An ideal route for the synthesis of the compound should produce the compound of formula (I) in high yields at a reasonable speed and at low cost with minimum waste materials and in a manner that is of minimum impact to the environment in terms of disposing of waste-materials and energy consumption.
We have found a new process for the synthesis of the compound of formula (I) with many advantages over previously known routes of synthesis. Such advantages include lower cost, less waste and more efficient use of materials. The new process enables advantageous preparation of the compound of formula (I) on a manufacturing scale.
The route of synthesis of the compound of formula (I) described in the specification of WO94/05639 is specifically described therein in examples 39A, 51A, 51B, 51C, 51D, 167 and 168. The overall yield from these examples is 33.2% of theory.
Generally the route described in WO94/05639 involves protecting the amino alcohol of formula (A) (Ex.39)
wherein P is a protecting group to form a compound of formula (B);
wherein P and P′ are each independently a protecting group;
deprotecting the compound of formula (B) to form a compound of formula (C) (Ex 51A);
wherein P′ is a protecting group;
forming a hydrochloride salt of compound (C) (Ex 51B) then reacting with N-imidazolyl-(S)-tetrahydrofuryl carbamate to form the compound of formula (D) (Ex 51C);
wherein P′ is a protecting group;
deprotecting the compound of formula (D) (Ex 51D) wherein P′ is a protecting group to form the compound of formula (D) wherein P′ is H (Ex 51E); and coupling the resultant secondary amine on the compound of formula (D) to a p-nitrophenylsulphonyl group to form a compound of formula (E) (Ex 167);
the resultant compound of formula (E) is then reduced to form the compound of formula (I) (Ex 168).
In summary, the process disclosed in WO94/05639 for producing the compound of formula (I) from the compound of formula (A) comprises 6 distinct stages:
1) protecting,
2) deprotecting,
3) reacting the resultant compound with an activated tetrahydrofuranol group,
4) deprotecting,
5) coupling with a p-nitrophenylsulfonyl group, and
6) reducing the resultant compound to form a compound of formula (I).
Applicants have now found a process by which the compound of formula (I) may be prepared on a manufacturing scale from the same starting intermediate, the compound of formula (A), in only 4 distinct stages instead of 6. In addition to the associated benefits of fewer stages, such as savings in time and cost, the improved process reduces the number of waste products formed. Furthermore, product may be obtained in a higher yield, of approximately 50% of theory
.
EXAMPLESExample 1
(1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(isobutylamino)propyl]carbamate (127.77 g, 379.7 mmol) was heated in toluene (888 ml) to 80° C. and triethylamine (42.6 g, 417.8 mmol) added. The mixture was heated to 90° C. and a solution of p-nitrobenzene sulphonyl chloride (94.3 g, 425.4 mmol) in toluene (250 ml) was added over 30 minutes then stirred for a further 2 hours. The resultant solution of the nosylated intermediate {(1S,2R)-tert-butyl N-[1-benzyl-2-hydroxy-3-(N-isobutyl- 4-nitrobenzenesulphonamido)propyl]carbamate } was then cooled to 80° C. The solution was maintained at approximately 80° C., and concentrated hydrochloric acid (31.4 ml, 376.8 mmol) was added over 20 minutes. The mixture was heated to reflux (approx 86° C.) and maintained at this temperature for an hour then a further quantity of concentrated hydrochloric acid (26.4 ml, 316.8 mmol) was added. Solvent (water and toluene mixture) was removed from the reaction mixture by azeotropic distillation (total volume of solvent removed approx 600 ml), and the resultant suspension was cooled to 70-75° C. Denatured ethanol (600 ml) was added, and the solution was cooled to 20° C. The mixture was further cooled to approximately −10° C. and the precipitate formed was isolated by filtration, washed with denatured ethanol (50 ml) and dried at approximately 50° C., under vacuum, for approximately 12 hours, to give (2R,3S)-N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutyl-4-nitrobenzene sulphonamide hydrochloride (160 g; 73% of theory yield corrected for assay). NMR: 1H NMR (300Mhz, dmso-d6): 8.37(2H, d, J=9 Hz), 8.16(NH3 +s), 8.06(2H, d, J=9 Hz), 7.31(5H, m), 5.65(1H, d, J=5 Hz), 3.95(1H, m), 3.39(2H, m), 2.95(5H, m), 1.90(1H, m), 0.77(6H, dd, J=21 Hz and 6 Hz).
1,1′-carbonyidiimidazole (27.66 kg, 170.58 mol) was added to ethyl acetate (314.3 kg) with stirring to give 3-(S)-tetrahydrofuryl imidazole-1-carboxylate. (S)-3-hydroxytetrahydrofuran (157 kg, 178.19 mol) was added over 30 minutes, washed in with ethyl acetate (9.95 kg), then the mixture was stirred for a further hour. (2R,3S)-N-(3-amino-2-hydroxy-4-phenylbutyl)-N-isobutyl-4-nitrobenzene sulphonamide hydrochloride (65.08 kg, 142.10 mol) was added and the mixture heated to reflux for approximately 22 hours. The solution was cooled slightly, and denatured ethanol (98 l) was added. The solution was stirred at 60° C. for 10 minutes then cooled and the product allowed to crystallise. The mixture was cooled to <10° C. and stirred for 2 hours. The product was isolated by filtration, washed with denatured ethanol (33 l) and dried at approximately 50° C., under vacuum to give (3S)-tetrahydro-3-furyl N-[(1S,2R)-1-benzyl-2-hydroxy-3-(N-isobutyl-4-nitrobenzene sulphonamido)propyl]carbamate in a yield of 82% of theory.
NMR: 1H NMR (500 Mhz, dmso-d6): 8.38(2H, d, J=9Hz), 8.06(2H, d, J=9 Hz), 7.20(6H, m), 5.02(1H, d, J=5 Hz), 4.94(1H, m), 4.35(EtOH, broad s), 3.71(EtOH, q), 3.65(1H, m), 3.60(1H, m), 3.51(2H, broad m), 3.40(2H, m), 3.15(1H, dd, J=8 Hz and 14 Hz), 3.07(1H, dd, J=8 Hz and 15 Hz), 2.94(2H, m), 2.48(1H, m), 2.06(1H, m), 1.97(1H, m), 1.78(1H, m), 1.05(EtOH, t), 0.83(6H, dd, J=7 Hz and 16 Hz).
Product from the above stage (80.0 g, 149.4 mmol) was hydrogenated in isopropanol (880 ml) with 5% palladium on carbon (16 g, of a wet paste) and hydrogen pressure (approx 0.5 to 1.5 bar) at 25-50° C. for approximately 5 hours. The mixture was cooled and the catalyst removed by filtration. The solution was distilled to a volume of approximately 320 ml and water (80 ml) was added. This solution was divided into two for the crystallisation step.
To half of the above solution, decolourising charcoal (2 g) was added, the mixture stirred at approximately 32° C. for 4 hours, then filtered. The filtercake was washed with isopropanol (20 ml) then further water (40 ml) was added to the filtrate. The solution was seeded to induce crystallisation and stirred for 5 hours. Water (130 ml) was added slowly over 1 hour then the mixture was stirred for 4 hours. The resultant slurry was cooled to approximately 20° C. and the product was isolated by filtration and washed with a 1:4 mixture of isopropano/water (120 ml). The product was dried at approximately 50° C., under vacuum, for approximately 12 hours to give (3S)-tetrahydro-3-furyl N-[(1S,2R)-3-(4-amino-N-isobutylbenzenesulphonamido)-1-benzyl-2-hydroxypropyl] carbamate (30.3 g; 80% of theory yield).
NMR: 1H NMR (300 Mhz, dmso-d6): 7.39(2H, d, J=9 Hz), 7.18(6H, m), 6.60(2H, d, J=9 Hz), 6.00(2H, s), 4.99(1H, d, J=6 Hz), 4.93(1H, ddt), 3.64(5H, m), 3.34(1H, m), 3.28(1H, dd, J=14 Hz and 3 Hz), 3.01(1H, m, J=14 Hz and 3 Hz), 2.91(1H, m), 2.66(2H, m), 2.50(1H, m), 2.05(1H, m), 1.94(1H, m), 1.78(1H, m), 0.81(6H, dd, J=16 Hz and 7 Hz). m/z: 506.2(M+H+)
Example 11Synthesis of Amprenavir (1)To a solution of carbamate nitro derivative 15 (0.05 g, 0.09 mmol) in 2 mL of EtOAc was added SnCl2.2H2O (0.1 g, 0.5 mmol) at 70° C. The reaction mixture was heated for 1 h until starting material disappeared and the solution cooled to room temperature. It was then poured into saturated aq. NaHCO3 solution and extracted with EtOAc. The organic extract was dried over anhyd. Na2SO4 and concentrated under reduced pressure. It was purified over chromatography using petroleum ether:EtOAc (3:2) to give amprenavir 1 (0.04 g, 90%).IR: (CHCl3, cm−1): υmax 757, 1090, 1149, 1316, 1504, 1597, 1633, 1705, 2960, 3371; 1H NMR (200 MHz, CDC3): δ 0.86 (d, J=5.7 Hz, 3H), 0.90 (d, J=6.6 Hz, 3H), 1.78-2.21 (m, 3H), 235-3.11 (m, 6H), 3.58-4.11 (m, 7H), 4.25 (s, 2H), 5.01 (br s, 1H), 5.07 (br s, 1H), 6.65 (d, J=8.4 Hz, 2H), 7.20-7.28 (m, 5H), 7.51 (d, J=8.4 Hz, 2H); 13C NMR (50 MHz, CDC3): δ 19.9, 20.2, 27.3, 32.8, 35.4, 35.7, 53.8, 55.0, 58.6, 66.8, 72.6, 73.2, 75.3, 114.0, 125.9, 126.5, 1280.4, 129.5, 137.7, 150.9, 155.9;
Anal. Calcd for C25H35N3O6S: C, 59.39; H, 6.98; N, 8.31; S, 6.34. Found: C, 59.36; H, 6.81; N, 8.25; S, 6.29%.
Want to know everything on vir series
click
http://drugsynthesisint.blogspot.in/p/vir-series-hep-c-virus-22.html
AND
http://medcheminternational.blogspot.in/p/vir-series-hep-c-virus.html
![[(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-hydroxy-1-phenylbutan-2-yl]carbamate NMR spectra analysis, Chemical CAS NO. 161814-49-9 NMR spectral analysis, [(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-hydroxy-1-phenylbutan-2-yl]carbamate H-NMR spectrum](https://i0.wp.com/pic11.molbase.net/nmr/nmr_image/2014-07-23/000/115/669/161814-49-9-1h.png)
![[(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-hydroxy-1-phenylbutan-2-yl]carbamate NMR spectra analysis, Chemical CAS NO. 161814-49-9 NMR spectral analysis, [(3S)-oxolan-3-yl] N-[(2S,3R)-4-[(4-aminophenyl)sulfonyl-(2-methylpropyl)amino]-3-hydroxy-1-phenylbutan-2-yl]carbamate C-NMR spectrum](https://i0.wp.com/pic11.molbase.net/nmr/nmr_image/2014-07-23/000/115/669/161814-49-9-13c.png)
COSY PREDICTION
See also
- Fosamprenavir, a prodrug of amprenavir
External links
- Amprenavir bound to proteins in the PDB
- Shen, C. H.; Wang, Y. F.; Kovalevsky, A. Y.; Harrison, R. W.; Weber, I. T. (2010). “Amprenavir complexes with HIV-1 protease and its drug-resistant mutants altering hydrophobic clusters”. FEBS Journal 277 (18): 3699–3714. doi:10.1111/j.1742-4658.2010.07771.x. PMC 2975871. PMID 20695887.
Want to know everything on vir series
click
http://drugsynthesisint.blogspot.in/p/vir-series-hep-c-virus-22.html
AND
http://medcheminternational.blogspot.in/p/vir-series-hep-c-virus.html
 |
|
| Systematic (IUPAC) name | |
|---|---|
| (3S)-oxolan-3-yl N-[(2S,3R)-3-hydroxy-4-[N-(2-methylpropyl)(4-aminobenzene)sulfonamido]-1-phenylbutan-2-yl]carbamate | |
| Clinical data | |
| Trade names | Agenerase |
| AHFS/Drugs.com | monograph |
| MedlinePlus | a699051 |
| Licence data | EMA:Link, US FDA:link |
|
|
| Legal status |
?
|
| Routes | oral |
| Pharmacokinetic data | |
| Protein binding | 90% |
| Metabolism | hepatic |
| Half-life | 7.1-10.6 hours |
| Excretion | <3% renal |
| Identifiers | |
| CAS number | 161814-49-9  |
| ATC code | J05AE05 |
| PubChem | CID 65016 |
| DrugBank | DB00701 |
| ChemSpider | 58532 |
| UNII | 5S0W860XNR |
| KEGG | D00894 |
| ChEBI | CHEBI:40050 |
| ChEMBL | CHEMBL116 |
| NIAID ChemDB | 006080 |
| Chemical data | |
| Formula | C25H35N3O6S |
| Molecular mass | 505.628 g/mol |
Sun Pharma to acquire GSK’s Australian opiates business
Sun Pharma to acquire GSK’s Australian opiates business
India-based Sun Pharmaceutical Industries has agreed to acquire GlaxoSmithKline’s (GSK) opiates business in Australia.
The agreement has been signed by wholly-owned subsidiaries of both firms, with the financial terms not disclosed.
Sun Pharma API business executive vice-president Iftach Seri said: “The global opiates market holds good potential and the addition of GSK’s Opiates business will strengthen our positioning further.”
Sun Pharmaceutical Industries Ltd(SUN.NS), India’s largest drugmaker by sales, said on Tuesday it has agreed to buy GlaxoSmithKline’s(GSK.L) opiates business in Australia to strengthen its pain management portfolio.
The business consists of analgesics made from raw materials found in opium poppy plants, and includes two manufacturing sites in the states of Tasmania and Victoria.
Financial details of the deal were not disclosed. A Sun Pharma spokesman declined to comment. Glaxo did not immediately respond to a request seeking comment.
Glaxo supplies a quarter of the world’s medicinal opiate needs from poppies grown by farmers in Tasmania, according to the company website. The company’s Australian opiates business brought in revenue of A$89 million ($69.63 million) in 2013.
Australia’s poppy industry is the world’s largest legal supplier of pharmaceutical grade opiates for painkillers, and Glaxo is one of three firms that control the crop and production in Tasmania.
The other two are Johnson & Johnson’s (JNJ.N) unit Tasmanian Alkaloids, and privately-held TPI Enterprises.
Glaxo’s decision to part with the opiates business comes as Tasmania’s poppy industry is facing a tough crop and the United Nations is expected to cut the state’s poppy crop area this week.
Glaxo said the deal would allow it to “focus on delivering its innovative product portfolio” in Australia.
“The opiates business has been an important part of our Australian business for many years, but as our portfolio transitions, we believe now is the right time to hand this business over to someone else,” Steve Morris, general manager of GSK Opiates, said in a statement.
The business employs 185 staff, including 155 in Victoria state and 30 in Tasmania state. Sun Pharma said it would hire all employees from both sites.
“The acquisition is a part of our strategy towards building our portfolio of opiates and accessing strong capabilities in this segment,” said Iftach Seri, executive vice president of the active pharmaceuticals ingredients business at Sun Pharma.
Both companies said they expect to close the deal by August.
Sun Pharma shares closed 1.93 percent higher on Tuesday, while the broader Nifty rose 0.44 percent.
($1 = 1.2781 Australian dollars)
Dacinostat (LAQ-824, NVP-LAQ824,)
C22H25N3O3
Exact Mass: 379.18959
Molecular Weight: 379.45
Reversible acetylation of histones is a major regulator of gene expression that acts by altering accessibility of transcription factors to DNA. In normal cells, histone deacetylase (HDA) and histone acetyltrasferase together control the level of acetylation of histones to maintain a balance. Inhibition of HDA results in the accumulation of hyperacetylated histones, which results in a variety of cellular responses.
Inhibitors of HDA have been studied for their therapeutic effects on cancer cells. For example, butyric acid and its derivatives, including sodium phenylbutyrate, have been reported to induce apoptosis in vitro in human colon carcinoma, leukemia and retinoblastoma cell lines. However, butyric acid and its derivatives are not useful pharmacological agents because they tend to be metabolized rapidly and have a very short half-life in vivo. Other inhibitors of HDA that have been widely studied for their anti-cancer activities are trichostatin A and trapoxin. Trichostatin A is an antifungal and antibiotic and is a reversible inhibitor of mammalian HDA. Trapoxin is a cyclic tetrapeptide, which is an irreversible inhibitor of mammalian HDA.
Although trichostatin and trapoxin have been studied for their anti-cancer activities, the in vivo instability of the compounds makes them less suitable as anti-cancer drugs. There remains a need for an active compound that is suitable for treating tumors, including cancerous tumors, that is highly efficacious and stable
|
References |
1: Wang H, Cheng F, Woan K, Sahakian E, Merino O, Rock-Klotz J, Vicente-Suarez I, Pinilla-Ibarz J, Wright KL, Seto E, Bhalla K, Villagra A, Sotomayor EM. Histone deacetylase inhibitor LAQ824 augments inflammatory responses in macrophages through transcriptional regulation of IL-10. J Immunol. 2011 Apr 1;186(7):3986-96. doi: 10.4049/jimmunol.1001101. Epub 2011 Mar 2. PubMed PMID: 21368229.
2: Schwarz K, Romanski A, Puccetti E, Wietbrauk S, Vogel A, Keller M, Scott JW, Serve H, Bug G. The deacetylase inhibitor LAQ824 induces notch signalling in haematopoietic progenitor cells. Leuk Res. 2011 Jan;35(1):119-25. doi: 10.1016/j.leukres.2010.06.024. Epub 2010 Jul 31. PubMed PMID: 20674020.
3: Cho YS, Whitehead L, Li J, Chen CH, Jiang L, Vögtle M, Francotte E, Richert P, Wagner T, Traebert M, Lu Q, Cao X, Dumotier B, Fejzo J, Rajan S, Wang P, Yan-Neale Y, Shao W, Atadja P, Shultz M. Conformational refinement of hydroxamate-based histone deacetylase inhibitors and exploration of 3-piperidin-3-ylindole analogues of dacinostat (LAQ824). J Med Chem. 2010 Apr 8;53(7):2952-63. doi: 10.1021/jm100007m. PubMed PMID: 20205394.
4: Vo DD, Prins RM, Begley JL, Donahue TR, Morris LF, Bruhn KW, de la Rocha P, Yang MY, Mok S, Garban HJ, Craft N, Economou JS, Marincola FM, Wang E, Ribas A. Enhanced antitumor activity induced by adoptive T-cell transfer and adjunctive use of the histone deacetylase inhibitor LAQ824. Cancer Res. 2009 Nov 15;69(22):8693-9. doi: 10.1158/0008-5472.CAN-09-1456. Epub 2009 Oct 27. PubMed PMID: 19861533; PubMed Central PMCID: PMC2779578.
5: Ellis L, Bots M, Lindemann RK, Bolden JE, Newbold A, Cluse LA, Scott CL, Strasser A, Atadja P, Lowe SW, Johnstone RW. The histone deacetylase inhibitors LAQ824 and LBH589 do not require death receptor signaling or a functional apoptosome to mediate tumor cell death or therapeutic efficacy. Blood. 2009 Jul 9;114(2):380-93. doi: 10.1182/blood-2008-10-182758. Epub 2009 Apr 21. PubMed PMID: 19383971.
6: de Bono JS, Kristeleit R, Tolcher A, Fong P, Pacey S, Karavasilis V, Mita M, Shaw H, Workman P, Kaye S, Rowinsky EK, Aherne W, Atadja P, Scott JW, Patnaik A. Phase I pharmacokinetic and pharmacodynamic study of LAQ824, a hydroxamate histone deacetylase inhibitor with a heat shock protein-90 inhibitory profile, in patients with advanced solid tumors. Clin Cancer Res. 2008 Oct 15;14(20):6663-73. doi: 10.1158/1078-0432.CCR-08-0376. PubMed PMID: 18927309.
7: Chung YL, Troy H, Kristeleit R, Aherne W, Jackson LE, Atadja P, Griffiths JR, Judson IR, Workman P, Leach MO, Beloueche-Babari M. Noninvasive magnetic resonance spectroscopic pharmacodynamic markers of a novel histone deacetylase inhibitor, LAQ824, in human colon carcinoma cells and xenografts. Neoplasia. 2008 Apr;10(4):303-13. PubMed PMID: 18392140; PubMed Central PMCID: PMC2288545.
8: Cuneo KC, Fu A, Osusky K, Huamani J, Hallahan DE, Geng L. Histone deacetylase inhibitor NVP-LAQ824 sensitizes human nonsmall cell lung cancer to the cytotoxic effects of ionizing radiation. Anticancer Drugs. 2007 Aug;18(7):793-800. PubMed PMID: 17581301.
9: Kato Y, Salumbides BC, Wang XF, Qian DZ, Williams S, Wei Y, Sanni TB, Atadja P, Pili R. Antitumor effect of the histone deacetylase inhibitor LAQ824 in combination with 13-cis-retinoic acid in human malignant melanoma. Mol Cancer Ther. 2007 Jan;6(1):70-81. PubMed PMID: 17237267.
10: Leyton J, Alao JP, Da Costa M, Stavropoulou AV, Latigo JR, Perumal M, Pillai R, He Q, Atadja P, Lam EW, Workman P, Vigushin DM, Aboagye EO. In vivo biological activity of the histone deacetylase inhibitor LAQ824 is detectable with 3′-deoxy-3′-[18F]fluorothymidine positron emission tomography. Cancer Res. 2006 Aug 1;66(15):7621-9. PubMed PMID: 16885362.
SEE MORE AT……….http://drugsynthesisint.blogspot.in/p/nostat-series.html
SEE MORE AT……….http://drugsynthesisint.blogspot.in/p/nostat-series.html
Sitasentan TBC 11251
Sitasentan,TBC 11251
210421-64-0
N-(4-chloro-3-methyl-1,2-oxazol-5-yl)-2-[2-(6-methyl-1,3-benzodioxol-5-yl)acetyl]thiophene-3-sulfonamide
Sitaxentan sodium (TBC-11251) is a medication for the treatment of pulmonary arterial hypertension (PAH).[1] It was marketed as Thelin by Encysive Pharmaceuticals until Pfizer purchased Encysive in February 2008. In 2010, Pfizer voluntarily removed sitaxentan from the market due to concerns about liver toxicity.[2]
Sitaxentan belongs to a class of drugs known as endothelin receptor antagonists (ERAs). Patients with PAH have elevated levels of endothelin, a potent blood vessel constrictor, in their plasma and lung tissue. Sitaxentan blocks the binding of endothelin to its receptors, thereby negating endothelin’s deleterious effects.
Mechanism of action
Sitaxentan is a small molecule that blocks the action of endothelin (ET) on the endothelin-A (ETA) receptor selectively (by a factor of 6000 compared to the ETB).[3] It is a sulfonamide class endothelin receptor antagonist (ERA) and is undergoing Food and Drug Administration (FDA) review for treating pulmonary hypertension. The rationale for benefit compared to bosentan, a nonselective ET blocker, is negligible inhibition of the beneficial effects of ETB stimulation, such as nitric oxide production and clearance of ET from circulation. In clinical trials, the efficacy of sitaxentan has been much the same as bosentan, but the hepatotoxicity of sitaxentan outweighs its benefits. Dosing is once daily, as opposed to twice daily for bosentan.
Regulatory status
On December 10, 2010 Pfizer announced it would be withdrawing sitaxentan worldwide (both from marketing and from all clinical study use), citing that it is a cause of fatal liver damage.[2]
Sitaxentan was approved for marketing in the European Union in 2006, in Canada in 2006[4] and in Australia in 2007. By February 2008 it had been launched commercially in Germany, Austria, The Netherlands, the United Kingdom, Ireland, France, Spain and Italy.
In March 2006, the FDA recommended an approvable status to sitaxentan but said it would not yet approve the product. In July 2006, sitaxentan received a second approvable letter stating that efficacy outcome issues raised in the context of the STRIDE-2 study were still unresolved. In July 2007, Encysive commenced a formal dispute resolution process in a preliminary meeting with the FDA. In September 2007 the company announced that it was making preparations for another phase III clinical trial (intended to be named STRIDE-5) to overcome the FDA’s concerns.[5] The takeover by Pfizer resulted in a reconfiguration and extension of these plans, to include combination therapy with sildenafil. The Sitaxentan Efficacy and Safety Trial With a Randomized Prospective Assessment of Adding Sildenafil (SR-PAAS) was an ongoing program of three clinical trials conducted in the United States (ClinicalTtrials.gov identifiers: NCT00795639, NCT00796666 and NCT00796510) with anticipated completion dates between June 2010 and January 2014.
N-(4-Chloro-3-methyl-5-isoxazolyl)-2-[2-(6-methyl-1,3-benzodioxol-5-yl)acetyl]-3-thiophenesulfonamide sodium salt, Sitaxsentan sodium salt, TBC-11251 sodium salt, Thelin
- CAS Number 210421-74-2
- Empirical Formula C18H14ClN2NaO6S2
- Molecular Weight 476.89
Adverse effects
Adverse effects observed with sitaxentan are class effects of endothelin receptor antagonists, and include :
- liver enzyme abnormalities (increased ALT and AST)
- headache
- edema
- constipation
- nasal congestion
- upper respiratory tract infection
- dizziness
- insomnia
- flushing
Because sitaxentan inhibits metabolism of warfarin, a decreased dose of warfarin is needed when co-administered with sitaxentan. This is because warfarin acts to prevent blood from clotting, and if it remains unmetabolized, it can continue to thin the blood.
http://www.google.com/patents/WO2007149568A2?cl=en
As used herein “sitaxsentan” refers to N-(4-chloro-3-methyl-5-isoxazolyl)-2-[2- methyl-4,5-(methylenedioxy)phenylacetyl]-thiophene-3-sulfonamide. Sitaxsentan is also known as TBCl 1251. Other chemical names for sitaxsentan include 4-chloro-3-methyl-5-(2- (2-(6-methylbenzo[d][l ,3]dioxol-5-yl)acetyl)-3-thienylsulfonamido)isoxazole and N-(4- chloro-3-methyl-5-isoxazolyl)-2-[3,4-(methylenedioxy)-6-methylphenylacetyl]-thiophene-3- sulfonamide.
The chemical name for sitaxsentan is N-(4-chloro-3-methyl-5-isoxazolyl)-2-[2- methyl-4,5-(methylenedioxy)phenylacetyl]-thiophene-3-sulfonamide, and its structural formula is as follows:
Sitaxsentan
Sitaxsentan is a potent endothelin receptor antagonist that has oral bioavailability in several species, a long duration of action, and high specificity for ETA receptors.
EXAMPLE 1
Preparation of 4-chloro-3-methyl-5-(2-(2-(6-methylbenzo[d] [l,3|dioxol-5-yl)aeetyl)-3- thienylsulfonamido)isoxazole, or N-(4-chloro-3-methyl-5-isoxazolyl)-2-[2-methy 1-4,5- (methylenedioxy)phenylacetyl]-thiophene-3-sulfonamide, or N-(4-chIoro-3-methyl-5- isoxazolyl)-2-[3,4-(methylenedioxy)-6-methylphenylacetyl]-thiophene-3-sulfonamide.
A. Preparation of (4-chIoro-3-methyl-5-(2-(2-(6-methylbenzo[d] [l,3]dioxol-5-yl)acetyl)- 3-thienylsuIfonamido)isoxazole 1. Preparation of 5-chloromethyI-6-methylbenzo[d][l,3]dioxole
To a mixture of methylene chloride (130 L), concentrated HCl (130 L), and tetrabuylammonium bromide (1.61 Kg) was added 5-methylbenzo[d][l,3]dioxole (10 Kg) followed by the slow addition of formaldehyde (14 L, 37 wt% in water). The mixture was stirred overnight. The organic layer was separated, dried with magnesium sulfate and concentrated to an oil. Hexane (180 L) was added and the mixture heated to boiling. The hot hexane solution was decanted from a heavy oily residue and evaporated to give almost pure 5-chloromethyl-6-methylbenzo[d][l,3]dioxole as a white solid. Recrystallization from hexane (50 L) gave 5-chloromethyl-6-methylbenzo[d][l,3]dioxole (80% recovery after recrystallization). 2. Formation of (4-chloro-3-methyl-5-(2-(2-(2-methyIbenzo[d][l,3]dioxol-5-yl) acetyl)-3-thienylsulfonamido)isoxazole
A portion of a solution of 5-chloromemyl-6-methylbenzo[d][l,3]di-oxole (16.8 g, 0.09 mol) in tetrahydrofuran (THF)(120 mL) was added to a well stirred slurry of magnesium powder, (3.3 g, 0.136 g-atom, Alfa, or Johnson-Mathey, -20 +100 mesh) in THF (120 mL) at room temperature. The resulting reaction admixture was warmed up to about 40-450C for about 2-3 min, causing the reaction to start. Once the heating activated the magnesium, and the reaction began, the mixture was cooled and maintained at a temperature below about 8 0C. The magnesium can be activated with dibromoethane in place of heat.
A flask containing the reaction mixture was cooled and the remaining solution of 5- chloromethlybenzo[d][l,3]dioxole added dropwise during 1.5 hours while maintaining an internal temperature below 8 0C. Temperature control is important: if the Grignard is generated and kept below 8 0C5 Wurtz coupling is suppressed. Longer times at higher temperatures promote the Wurtz coupling pathway. Wurtz coupling can be avoided by using high quality Mg and by keeping the temperature of the Grignard below about 8 0C and stirring vigorously. The reaction works fine at -20 0C, so any temperature below 8 0C is acceptable at which the Grignard will form. The color of the reaction mixture turns greenish.
The reaction mixture was stirred for an additional 5 min at 0 0C, while N2-methoxy- N2-methyl-3-(4-chloro-3-methyl-5-isoazolylsulfamoyl)-2-thiophenecarboxamide (6.6 g, 0.018 mol) in anhydrous THF (90 mL) was charged into the addition funnel. The reaction mixture was degassed two times then the solution of N2-methoxy-N2-methyl-3-(4-chloro-3- methyl-5-isoxazolylsulfamoyl)-2-thiophenecarboxamide was added at 0 0C over 5 min. TLC of the reaction mixture (Silica, 12% MeOHZCH2Cl2) taken immediately after the addition shows no N2-methoxy-N2-methyl-3-(4-chloro-3-methyl-5-isoxazolysulfamoyl)-2-thio- phenecarboxamide. The reaction mixture was transferred into a flask containing IN HCl (400 mL, 0.4 mol
HCl, ice-bath stirred), and the mixture stirred for 2 to 4 min, transferred into a separatory funnel and diluted with ethyl acetate (300 mL). The layers were separated after shaking. The water layer was extracted with additional ethyl acetate (150 mL) and the combined organics washed with half-brine. Following separation, THF was removed by drying the organic layer over sodium sulfate and concentrating under reduced pressure at about 39 0C to obtain the title compound. EXAMPLE 2
1.0 g Sitaxentan was dissolved in 10 ml ethyl acetate and 5 ml hexanes were added. The formed suspension was heated until a clear solution was obtained. Upon cooling light yellow plates were formed. After filtration and drying under vacuum 515 mg of sitaxentan polymorph A was obtained as light yellow plates in very high purity.
EXAMPLE 3
Preparation of 4-chloro-3-methyl-5-(2-(2-(6-methyIbenzo[dJ [l,3]dioxol-5-yl)acetyl)-3- thienylsulfonamido)isoxazole, Sodium Salt
The crystalline sitaxsentan from Example 2 is dissolved in ethyl acetate and washed with saturated NaHCO3 (5 x 10 mL). The solution is washed with brine, dried over Na2SO4 and concentrated in vacuo to obtain a solid residue. 10 mL OfCH2Cl2 is added and the mixture is stirred under nitrogen for 5 to 10 minutes. Ether (15 mL) is added and the mixture stirred for about 10 min. The product is isolated by filtration, washed with a mixture of CH2Cl2 /ether (1 :2) (10 mL) then with ether (10 mL) and dried under reduced pressure to obtain 4-Chloro-3-methyl-5-(2-(2-(6-methyIbenzo[d][l ,3]dioxol-5-yl)acetyl)-3- thienylsulfonamido)isoxazole, sodium salt.
………………………..
Yingyong Huaxue (2007), 24, (11), 1310-1313. Publisher: (Kexue Chubanshe, ) CODEN:YIHUED ISSN:1000-0518.
Table 1: Sitaxsentan Sodium Lyophilized Formulation
References
- 2
- Citing liver damage, Pfizer withdraws Thelin, Associated Press, December 12, 2010
- 3
- Girgis, RE; Frost, AE; Hill, NS; Horn, EM; Langleben, D; McLaughlin, VV; Oudiz, RJ; Robbins, IM et al. (2007). “Selective endothelinA receptor antagonism with sitaxsentan for pulmonary arterial hypertension associated with connective tissue disease”. Annals of the rheumatic diseases 66 (11): 1467–72. doi:10.1136/ard.2007.069609. PMC 2111639. PMID 17472992.
- 4
- “UPDATE 1-Encysive gets Canadian approval for hypertension drug”. Reuters. 30 May 2007. Retrieved 2007-07-08.
- 5
- “Encysive Pharmaceuticals to Conduct Phase III Study With Thelin (Sitaxsentan Sodium) in Pulmonary Arterial Hypertension”. PrimeNewswire via COMTEX News Network. 29 September 2007. Retrieved 2007-12-12.
External links
- http://www.drugs.com/nda/thelin_050714.html
- Mucke HAM: Sitaxsentan for the Oral Treatment of Pulmonary Arterial Hypertension: Benefits from Endothelin Receptor Subtype Selectivity? Clinical Medicine: Therapeutics 2009:1 111–121.
- ATS 2005. The International Conference of the American Thoracic Society. 20–25 May 2005. San Diego, CA.
- Robyn J. Barst, MD; Stuart Rich, MD, FCCP; Allison Widlitz, MS, PA; Evelyn M. Horn, MD; Vallerie McLaughlin, MD and Joyce McFarlin, RN : Clinical Efficacy of Sitaxsentan, an Endothelin-A Receptor Antagonist, in Patients With Pulmonary Arterial Hypertension Chest. 2002;121:1860-1868.
- American Heart Association. Primary or Unexplained Pulmonary Hypertension
| US20010021714 * | Apr 4, 1996 | Sep 13, 2001 | Ming Fai Chan | Compounds such as n-(4-bromo-3-methyl-5-isoxazolyl)-2-n-benzylbenzo(b)thiophene-3-sufonamide administered as endothelin peptide receptor antagonists |
| Reference | ||
|---|---|---|
| 1 | * | WU C ET AL: “Discovery of TBC11251, a Potent, Long Acting, Orally Active Endothelin Receptor-A Selective Antagonist” JOURNAL OF MEDICINAL CHEMISTRY, AMERICAN CHEMICAL SOCIETY. WASHINGTON, US, vol. 40, no. 11, 23 May 1997 (1997-05-23), pages 1690-1697, XP002164198 ISSN: 0022-2623 |
| Patent | Submitted | Granted |
|---|---|---|
| ANTIHYPERTENSIVE THERAPY METHOD [US2007293552] | 2007-12-20 | |
| Crystalline N-(4-chloro-3-methyl-5-isoxazolyl)-2-[2-methyl-4.5-(methylenedioxy)phenylacetyl]-thiophene-3-sulfonamide [US2008026061] | 2008-01-31 | |
| Gnrh agonist combination drugs [US2005215528] | 2005-09-29 | |
| THIENYL-, FURYL-, PYRROLYL- AND BIPHENYLSULFONAMIDES AND DERIVATIVES THEREOF THAT MODULATE THE ACTIVITY OF ENDOTHELIN [WO9631492] | 1996-10-10 | |
| SULFONAMIDES FOR TREATMENT OF ENDOTHELIN-MEDIATED DISORDERS [WO9849162] | 1998-11-05 |
| Patent | Submitted | Granted |
|---|---|---|
| Respiratory Drug Condensation Aerosols and Methods of Making and Using Them [US2009258075] | 2009-10-15 | |
| Method and Composition for Treating Alzheimer’s Disease and Dementias of Vascular Origin [US2010173872] | 2010-07-08 | |
| Method and Composition for Treating Alzheimer’s Disease and Dementias of Vascular Origin [US2010184725] | 2010-07-22 | |
| Formulations of sitaxsentan sodium [US2008076812] | 2008-03-27 | |
| Methods and compositions for treatment of sleep apnea [US2008085313] | 2008-04-10 | |
| Processes for the preparation of 4-chloro-3-methyl-5-(2-(2-(6-methylbenzo[d][1,3]dioxol-5-yl)acetyl)-3-thienylsulfonamido)isoxazole [US2008086010] | 2008-04-10 | |
| Method and composition for treating alzheimer’s disease and dementias of vascular origin [US2004092427] | 2004-05-13 | |
| Method for preventing or treating pulmonary inflammation by administering an endothelin antagonist [US2003004199] | 2003-01-02 | |
| Methods and Compositions for Treatment of an Interstitial Lung Disease [US2009004268] | 2009-01-01 | |
| Methods and compositions for treatment of diastolic heart failure [US2007232671] | 2007-10-04 | |
| Patent | Submitted | Granted |
|---|---|---|
| Isoxazolyl endothelin antagonists [US6043265] | 2000-03-28 | |
| Aminoguanidine hydrazone derivatives, process for producing the same and drugs thereof [US6350749] | 2002-02-26 | |
| Method for preventing or treating pain by administering an endothelin antagonist [US6573285] | 2002-06-27 | 2003-06-03 |
| Method for preventing or treating erectile dysfunction by administering an endothelin antagonist [US6268388] | 2001-07-31 | |
| Method and composition for potentiating the antipyretic action of a nonopioid analgesic [US7351692] | 2003-12-25 | 2008-04-01 |
| Method and Composition for Potentiating an Opiate Analgesic [US8114896] | 2010-05-06 | 2012-02-14 |
| SUBSTITUTED THIOPHENES [US7863308] | 2008-10-16 | 2011-01-04 |
| Respiratory drug condensation aerosols and methods of making and using them [US7550133] | 2004-06-03 | 2009-06-23 |
| SUBSTITUTED THIOPHENES [US2010280086] | 2010-11-04 | |
| Method and Composition for Potentiating an Opiate Analgesic [US2010311665] | 2010-12-09 |
 |
|
| Systematic (IUPAC) name | |
|---|---|
| N-(4-chloro-3-methyl-1,2-oxazol-5-yl)-2-[2-(6-methyl-2H-1,3-benzodioxol-5-yl)acetyl]thiophene-3-sulfonamide | |
| Clinical data | |
| AHFS/Drugs.com | International Drug Names |
| Licence data | EMA:Link |
| Legal status | |
| Routes | Oral |
| Pharmacokinetic data | |
| Bioavailability | 70 to 100% |
| Protein binding | >99% |
| Metabolism | Hepatic (CYP2C9– and CYP3A4-mediated) |
| Half-life | 10 hours |
| Excretion | Renal (50 to 60%) Fecal (40 to 50%) |
| Identifiers | |
| CAS number | 184036-34-8 210421-64-0 (sodium salt) |
| ATC code | C02KX03 |
| PubChem | CID 216235 |
| IUPHAR ligand | 3950 |
| DrugBank | DB06268 |
| ChemSpider | 21106381 |
| UNII | J9QH779MEM |
| KEGG | D07171 |
| ChEMBL | CHEMBL282724 |
| Synonyms | Sitaxsentan; TBC-11251 |
| Chemical data | |
| Formula | C18H15ClN2O6S2 |
| Molecular mass | 454.906 g/mol |
Structures and observed activities of the ETA receptor antagonists for the HipHop training set
COCK WILL TEACH YOU NMR
COCK SAYS MOM CAN TEACH YOU NMR
DRUG APPROVALS BY DR ANTHONY MELVIN CRASTO …..FOR BLOG HOME CLICK HERE
amcrasto@gmail.com
TAKE A TOUR
KISUMU, KENYA
Kisumu – Wikipedia, the free encyclopedia
Kisumu is a port city in Kisumu County, Kenya 1,131 m (3,711 ft), with a population of 409,928 (2009 census). It is the third largest city in Kenya, the principal city …
Kisumu CountyKisumu County is one of the new devolved counties of Kenya. Its …
|
Kisumu International AirportKisumu International Airport is an airport in Kisumu, Kenya (IATA …
|
Boat riding in Kisumu
Local inhabitants near Kisumu, 1911
Clockwise: Lake Victoria Panorama, Kisumu Panorama, sunset at Oginga Odinga street, Downtown, Kiboko Point, Nighttime in Kisumu and Jomo Kenyatta Stadium.
|
|
 Kisumu
|
|
Coordinates:  0°6′S 34°45′E |
|
| Country |  Kenya |
|---|---|
| County | Kisumu County |
Kisumu panorama, viewed from Lake Victoria
Jomo Kenyatta Stadium
Kisumu Harbour. The green vegetation is water hyacinth
Nairobi University Kisumu Campus
WANT TO KNOW ON SENTAN SERIES
MEDICINAL CHEMISTRY AT ITS BEST, Tracks information on drugs on worldwide basis by Dr Anthony Melvin Crasto, worlddrugtracker, helping millions with websites, 6 million hits on google, one lakh connections worldwide, email amcrasto@gmail.com, call +91 9323115463 India
READ MORE ON SENTAN SERIES……http://medcheminternational.blogspot.in/p/sentan-series.html
| Antagonists of Endothelin type A receptor ETA | |
| Name | Structure |
| BQ-123 |  |
| Bosentan |  |
| Atrasentan |  |
| Tezosentan |  |
| Sitaxsentan | |
| Darusentan |  |
| Clazosentan |  |
| ZD-4054 (Zibotentan) |  |
| Ambrisentan |  |
| Tak-044 |  |
| Avosentan |  |
MAHABALIPURAM, INDIA
Mahabalipuram – Wikipedia, the free encyclopedia
Mahabalipuram, also known as Mamallapuram is a town in Kancheepuram district in the Indian state of Tamil Nadu. It is around 60 km south from the city of …Shore Temple – Seven Pagodas – Pancha Rathas –
.
.
Krishna’s Butter Ball in Mahabalipuram, India. The surface below the rock is …
http://www.weather-forecast.com/locations/Mamallapuram
Come to Mahabalipuram (also known as Mammallapuram), an enchanting beach that is located on the east coast of India.
Moonraikers Restaurant, Mamallapuram
Hotel Mamalla Bhavan – Mahabalipuram Chennai – Food, drink and entertainment
.
A carving at the Varaha Temple, Mahabalipuram
/////////////
Atrasentan
Atrasentan
- 173937-91-2
- as HCl: 195733-43-8
A-147627, (+)-A-127722, ABT-627,173937-91-2,
(2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)pyrrolidine-3-carboxylic acid
Endothelin ET-A antagonist
Diabetic nephropathy; End stage renal disease; Renal disease
FDA APPROVED 4/02/2025, Vanrafia, To reduce proteinuria in adults with primary immunoglobulin A nephropathy at risk of rapid disease progression
- (2R,3R,4S)-4-(Benzo[d][1,3]dioxol-5-yl)-1-(2-(dibutylamino)-2-oxoethyl)-2-(4-methoxyphenyl)pyrrolidine-3-carboxylic acid
- (2R,3R,4S)-4-Benzo[1,3]dioxol-5-yl-1-dibutylcarbamoylmethyl-2-(4-methoxy-phenyl)-pyrrolidine-3-carboxylic acid
- 3-Pyrrolidinecarboxylic acid, 4-(1,3-benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)-, (2alpha,3beta,4alpha)-
- 3-Pyrrolidinecarboxylic acid, 4-(1,3-benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)-, (2R,3R,4S)-rel-
- 4-(1,3-Benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)-3-pyrrolidinecarboxylic acid, (2R,3R,4S)-rel-
- rel-(2R,3R,4S)-4-(Benzo[d][1,3]dioxol-5-yl)-1-(2-(dibutylamino)-2-oxoethyl)-2-(4-methoxyphenyl)pyrrolidine-3-carboxylic acid
| Ingredient | UNII | CAS | InChI Key |
|---|---|---|---|
| Atrasentan hydrochloride | E4G31X93ZA | 195733-43-8 | IJFUJIFSUKPWCZ-SQMFDTLJSA-N |
Atrasentan is an experimental drug that is being studied for the treatment of various types of cancer,[1] including non-small cell lung cancer.[2] It is also being investigated as a therapy for diabetic kidney disease.
Atrasentan failed a phase 3 trial for prostate cancer in patients unresponsive to hormone therapy.[3] A second trial confirmed this finding.[4]
It is an endothelin receptor antagonist selective for subtype A (ETA). While other drugs of this type (sitaxentan, ambrisentan) exploit the vasoconstrictive properties of endothelin and are mainly used for the treatment of pulmonary arterial hypertension, atrasentan blocks endothelin induced cell proliferation.
In April 2014, de Zeeuw et al. showed that 0.5 mg and 1.25 mg of atrasentan reduced urinary albumin by 35 and 38% respectively with modest side effects. Patients also had decreased home blood pressures (but no change in office readings) decrease total cholesterol and LDL. Patients in the 1.25 mg dose group had increased weight gain which was presumably due to increased edema and had to withdraw from the study more than the placebo or 0.5 mg dose group.[5] Reductions in proteinuria have been associated with beneficial patient outcomes in diabetic kidney disease with other interventions but is not an accepted end-point by the FDA.
The recently initiated SONAR trial[6] will determine if atrasentan reduces kidney failure in diabetic kidney disease.
Useful for treating nephropathy and chronic kidney disease associated with Type II diabetes. For a prior filing see WO2015006219 , claiming the stable solid composition in the form of a tablet comprising atrasentan and an anti-oxidant. AbbVie (following its spin-out from Abbott), is developing atrasentan (phase III; February 2015) for treating chronic kidney disease, including diabetic nephropathy.
PAPER
European Journal of Organic Chemistry
Enantioselective Synthesis of the Pyrrolidine Core of Endothelin Antagonist ABT-627 (Atrasentan) via 1,2-Oxazines
Year:2003
Volume:2003
Issue:18
page:3524-3533
PATENT
http://www.google.com/patents/US20080132710
EXAMPLE 1
A mixture of bromoacetyl bromide (72.3 mL) in toluene (500 mL) at 0° C. was treated with dibutylamine (280 mL) in toluene (220 mL) while keeping the solution temperature below 10° C., stirred at 0° C. for 15 minutes, treated with 2.5% aqueous phosphoric acid (500 mL) and warmed to 25° C. The organic layer was isolated, washed with water (500 mL) and concentrated to provide the product as a solution in toluene.
EXAMPLE 25-((E)-2-nitroethenyl)-1,3-benzodioxole
3,4-methylenedioxybenzaldehyde (15.55 Kg) was treated sequentially with ammonium acetate (13.4 Kg,), acetic acid (45.2 Kg) and nitromethane (18.4 Kg), warmed to 70° C., stirred for 30 minutes, warmed to 80° C., stirred for 10 hours, cooled to 10° C. and filtered. The filtrant was washed with acetic acid (2×8 Kg) and water (2×90 Kg) and dried under a nitrogen stream then in under vacuum at 50° C. for 2 days.
EXAMPLE 3ethyl 3-(4-methoxyphenyl)-3-oxopropanoate
A mixture of potassium tert-amylate (50.8 Kg) in toluene (15.2 Kg) at 5° C. was treated with 4-methoxyacetophenone (6.755 Kg) and diethyl carbonate (6.4 Kg) in toluene over 1 hour while keeping the solution temperature below 10° C., warmed to 60° C. for 8 hours, cooled to 20° C. and treated with acetic acid (8 Kg) and water (90 Kg) over 30 minutes while keeping the solution temperature below 20° C. The organic layer was isolated, washed with 5% aqueous sodium bicarbonate (41 Kg) and concentrated at 50° C. to 14.65 Kg.
EXAMPLE 4ethyl 2-(4-methoxybenzoyl)-4-nitromethyl-3-(1,3-benzodioxol-5-yl)butyrate
A mixture of EXAMPLE 3 (7.5 Kg) in THF (56 Kg) was treated with EXAMPLE 3 (8.4 Kg), cooled to 17° C., treated with sodium ethoxide (6.4 g), stirred for 30 minutes, treated with more sodium ethoxide (6.4 g), stirred at 25° C. until HPLC shows less than 1 area % ketoester remaining and concentrated to 32.2 Kg.
EXAMPLE 5ethyl cis,cis-2-(4-methoxyphenyl)-4-(1,3-benzodioxol-5-yl)pyrrolidine-3-carboxylate
Raney nickel (20 g), from which the water had been decanted, was treated sequentially with THF (20 mL), EXAMPLE 4 (40.82 g), and acetic acid (2.75 mL). The mixture was stirred under hydrogen (60 psi) until hydrogen uptake slowed, treated with trifluoroacetic acid, stirred under hydrogen (200 psi) until HPLC shows no residual imine and less than 2% nitrone and filtered with a methanol (100 mL) wash. The filtrate, which contained 13.3 g of EXAMPLE 5, was concentrated with THF (200 mL) addition to 100 mL, neutralized with 2N aqueous NaOH (50 mL), diluted with water (200 mL), and extracted with ethyl acetate (2×100 mL). The extract was used in the next step.
EXAMPLE 6ethyl trans,trans-2-(4-methoxyphenyl)-4-(1,3 -benzodioxol-5 -yl)pyrrolidine-3-carboxylate
Example 501E (38.1 g) was concentrated with ethanol (200 mL) addition to 100 mL, treated with sodium ethoxide (3.4 g), heated to 75° C., cooled to 25° C. when HPLC showed less than 3% of EXAMPLE 1E and concentrated. The concentrate was mixed with isopropyl acetate (400 mL), washed with water (2×150 mL) and extracted with 0.25 M phosphoric acid (2×400 mL). The extract was mixed with ethyl acetate (200 mL) and neutralized to pH 7 with sodium bicarbonate (21 g), and the organic layer was isolated.
EXAMPLE 7ethyl (2R,3R,4S)-(+)-2-(4-methoxyphenyl)-4-(1,3-benzodioxol-5-yl)pyrrolidine-3-carboxylate, (S)-(+) mandelate
EXAMPLE 501F was concentrated with acetonitrile (100 mL) addition to 50 mL, treated with (S)-(+)-mandelic acid (2.06 g), stirred until a solution formed, stirred for 16 hours, cooled to 0° C., stirred for 5 hours and filtered. The filtrant was dried at 50° C. under a nitrogen stream for 1 day. The purity of the product was determined by chiral HPLC using Chiralpak AS with 95:5:0.05 hexane/ethanol/diethylamine, a flow rate of 1 mL/min. and UV detection at 227 nm. Retention times were 15.5 minutes for the (+)-enantiomer and 21.0 minutes for the (−)-enantiomer.
EXAMPLE 8(2R,3R,4S)-(+)-2-(4-methoxyphenyl)-4-(1,3-benzodioxol-5-yl)-1-(N,N-di(n-butyl)aminocarbonylmethyl)pyrrolidine-3-carboxylic acid
A mixture of EXAMPLE 7 (20 g) in ethyl acetate (150 mL) and 5% aqueous sodium bicarbonate was stirred at 25° C. until the salt dissolved and gas evolution stopped. The organic layer was isolated and concentrated. The concentrate was treated with acetonitrile (200 mL), concentrated to 100 mL, cooled to 10° C., treated with diisopropylethylamine (11.8 mL) and EXAMPLE 1 (10.5 g), stirred for 12 hours and concentrated. The concentrate was treated with ethanol (200 mL), concentrated to 100 mL, treated with 40% aqueous NaOH (20 mL), stirred at 60° C. for 4 hours, cooled, poured into water (400 mL), washed with hexanes (2×50 mL then 2×20 mL), treated with ethyl acetate (400 mL) and adjusted to pH 5 with concentrated HCl (12 mL). The organic layer was isolated and concentrated.
………………….
SYN
Condensation of ketoester (I) with nitrovinyl benzodioxole (II) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene gave adduct (III). Hydrogenation of the nitro group of (III) over Raney Nickel with concomitant cyclization yielded dihydropyrrole (IV). Further reduction of (IV) with sodium cyanoborohydride provided a mixture of diastereomeric pyrrolidines. Chromatographic separation removed the cis,cis isomer, affording a mixture of trans,trans and cis,trans products (V). N-Alkylation of the pyrrolidine (V) with N,N-dibutyl bromoacetamide (VI) furnished (VIIa-b). Finally, selective hydrolysis of the ester group from the trans,trans isomer produced a mixture of cis,trans ester (VIII) and the target trans,trans acid, which were readily separated by fractional extraction.
SYN
SYN
J Med Chem 1996,39(5),1039
The Michael reaction between 3,4-(methylenedioxy)-beta-nitrostyrene (I) and ethyl (4-methoxybenzoyl)acetate (II) in the presence of DBU gave adduct (III) as a mixture of isomers. Hydrogenation of this nitro ketone over Raney-Ni afforded, after spontaneous cyclization of the resulting amino ketone, the pyrroline (IV). Further reduction of the imine with NaBH3CN yielded a mixture of three pyrrolidine isomers. The desired trans-trans isomer (VI) could not be separated from the cis-trans isomer by column chromatography. However, the pure cis-cis compound (V) was isomerized to (VI) with NaOEt in refluxing EtOH. The protection of the amine as the tert-butyl carbamate with Boc2O, and saponification of the ester function provided the racemic acid (VII). Resolution of (VII) was achieved by conversion to the mixed anhydride (VIII) with pivaloyl chloride, followed by condensation with the lithium salt of (S)-4-benzyl-2-oxazolidinone (IX), and chromatographic separation of the resulting diastereomeric imides. Alternatively, racemic (VII) could be resolved by crystallization of its salt with (R)-a-methylbenzylamine. Removal of the Boc group from the appropriate isomer (X) with HCl in dioxan, followed by alkylation with N,N-dibutylbromoacetamide (XI) in the presence of i-Pr2NEt furnished the pyrrolidinylacetamide (XII). Finally, hydrolysis of the imide with lithium hydroperoxide provided the target acid.
SYN
Reaction of 2-(1,3-dioxol-5-yl)acetic acid (XXI) with pivaloyl chloride and TEA gives the corresponding anhydride (XXII), which is condensed with the chiral oxazolidinone (XXIII) by means of n-BuLi in THF to yield the amide (XXIV). Condensation of (XXIV) with 2-bromoacetic acid tert-butyl ester (XXV) by means of NaHMDS in THF affords the adduct (XXVI). Elimination of the chiral auxiliary of (XXVI) by means of LiOOH in THF/water provides the chiral succinic acid hemiester (XXVII) (93% ee), which is selectively reduced with BH3璗HF complex to give the 4-hydroxysuccinate (XXVIII). Reaction of succinate (XXVIII) with 4-chlorophenylsulfonyl chloride, TEA and DMAP in dichloromethane yields the sulfonate (XXIX), which is condensed with 4-methoxybenzaldoxime (XXX) by means of Cs2CO3 in hot acetonitrile to afford the oxime ether (XXXI). Transesterification of the tert-butyl ester of (XXXI) with trimethyl orthoformate and p-toluenesulfonic acid in hot methanol provides the methyl ester (XXXII), which is cyclized by means of trimethylsilyl triflate and tributylamine in dichloroethane to afford a 9:1 diastereomeric mixture of perhydro-1,2-oxazines (XXXIII) and (XXXIV) which is easily separated. The reductive N-O-bond cleavage of the major oxazine diastereomer (XXXIII) by means of Zn/HOAc or H2 over Pd/C gives the trisubstituted 4-aminobutanol (XXXV), which is cyclized by means of CBr4, PPh3 and TEA to yield chiral pyrrolidine (XXXVI) (4). Finally, pyrrolidine (XXXVI) is alkylated with N,N-dibutyl-2-bromoacetamide (XIII) followed by ester hydrolysis as before.
References
1
- “Atrasentan”. NCI Dictionary of Cancer Terms. National Institute of Cancer.
- 2
- Chiappori, Alberto A.; Haura, Eric; Rodriguez, Francisco A.; Boulware, David; Kapoor, Rachna; Neuger, Anthony M.; Lush, Richard; Padilla, Barbara; Burton, Michelle; Williams, Charles; Simon, George; Antonia, Scott; Sullivan, Daniel M.; Bepler, Gerold (March 2008). “Phase I/II Study of Atrasentan, an Endothelin A Receptor Antagonist, in Combination with Paclitaxel and Carboplatin as First-Line Therapy in Advanced Non–Small Cell Lung Cancer”. Clinical Cancer Research 14 (5): 1464–9. doi:10.1158/1078-0432.CCR-07-1508. PMID 18316570.
- 3
- “Addition of experimental drug to standard chemotherapy for advanced prostate cancer shows no benefit in phase 3 clinical trial” (Press release). National Cancer Institute. April 21, 2011. Retrieved October 18, 2014.
- 4
- Quinn, David I; Tangen, Catherine M; Hussain, Maha; Lara, Primo N; Goldkorn, Amir; Moinpour, Carol M; Garzotto, Mark G; Mack, Philip C; Carducci, Michael A; Monk, J Paul; Twardowski, Przemyslaw W; Van Veldhuizen, Peter J; Agarwal, Neeraj; Higano, Celestia S; Vogelzang, Nicholas J; Thompson, Ian M (August 2013). “Docetaxel and atrasentan versus docetaxel and placebo for men with advanced castration-resistant prostate cancer (SWOG S0421): a randomised phase 3 trial”. The Lancet Oncology 14 (9): 893–900. doi:10.1016/S1470-2045(13)70294-8. PMID 23871417.
- 5
- de Zeeuw, Dick; Coll, Blai; Andress, Dennis; Brennan, John J.; Tang, Hui; Houser, Mark; Correa-Rotter, Ricardo; Kohan, Donald; Lambers Heerspink, Hiddo J.; Makino, Hirofumi; Perkovic, Vlado; Pritchett, Yili; Remuzzi, Giuseppe; Tobe, Sheldon W.; Toto, Robert; Viberti, Giancarlo; Parving, Hans-Henrik (May 2014). “The endothelin antagonist atrasentan lowers residual albuminuria in patients with type 2 diabetic nephropathy”. Journal of the American Society of Nephrology 25 (5): 1083–93. doi:10.1681/ASN.2013080830. PMID 24722445.
- 6
Clinical trial number NCT01858532 for “Study Of Diabetic Nephropathy With Atrasentan (SONAR)” at ClinicalTrials.gov
Granted in February 2015, this patent claims novel crystalline anhydrous S-mandelate salt of atrasentan. Useful for treating nephropathy and chronic kidney disease associated with Type II diabetes.
 |
|
| Systematic (IUPAC) name | |
|---|---|
| (2R,3R,4S)-4-(1,3-Benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)pyrrolidine-3-carboxylic acid | |
| Clinical data | |
| Legal status |
?
|
| Identifiers | |
| CAS number | 173937-91-2  |
| ATC code | None |
| PubChem | CID 159594 |
| ChemSpider | 140321 |
| UNII | V6D7VK2215 |
| ChEMBL | CHEMBL9194 |
| Chemical data | |
| Formula | C29H38N2O6 |
| Molecular mass | 510.621 g/mol |
READ MORE ON SENTAN SERIES………..http://medcheminternational.blogspot.in/p/sentan-series.html
- Szczepankiewicz BG, Bal RB, von Geldern TW, Wu-Wong JR, Chiou WJ, Dixon DB, Opgenorth TJ, Hoffman DJ, Borre AJ, Marsh KC, Nguyen BN: The effects of diminishing albumin binding to some Endothelin receptor antagonists. Life Sci. 1998;63(21):1905-12. doi: 10.1016/s0024-3205(98)00466-4. [Article]
- Rajasekaran A, Julian BA, Rizk DV: IgA Nephropathy: An Interesting Autoimmune Kidney Disease. Am J Med Sci. 2021 Feb;361(2):176-194. doi: 10.1016/j.amjms.2020.10.003. Epub 2020 Oct 8. [Article]
- FDA Approved Drug Products: Vanrafia (atrasentan) tablets for oral use (April 2025) [Link]
- Novartis Media Release: Novartis receives FDA accelerated approval for Vanrafia® (atrasentan), the first and only selective endothelin A receptor antagonist for proteinuria reduction in primary IgA nephropathy (IgAN) [Link]
- StatPearls [Internet]: IgA Nephropathy (Berger Disease) [Link]
- ResearchGate: Total Synthesis of Atrasentan (Craig S. Harris, Reims Symposium, October 2002) [Link]
//////////ATRASENTAN, FDA 2025, APPROVALS 2025, Vanrafia, A 147627, (+)-A-127722, ABT 627, UNII-V6D7VK2215
SWINE FLU ; AYURVEDA SUCCESSFUL TREATMENT ; स्वाइन प्लू का सुरक्षित आयुर्वेदिक इलाज
स्वाइन प्लू के लक्षणो पर आधारित सभी रोगियो का आयुर्वेदिक इलाज करने के बाद यह अनुभव मे आया है कि महामारी की तरह फैल रही बीमारी का बहुत सटीक और अचूक इलाज आयुर्वेद मे है /
वायरल / अथवा स्वाइन फ्लू के रोगियो के इलाज मे मैने निम्न दवाये दी है उन्हे मै सार्वजनिक तौर पर देश के सभी नागरिको के लिये यहा बता रहा हू /
स्वाइन फ्लू या इस जैसी बीमारी के इलाज के लिये मेरा नुस्खा इस तरह है /
-
महामृत्युन्जय रस दो गोली
-
कफ कुठार रस चार गोली
-
सुदर्शन घन वटी दो गोली
-
सप्त पर्ण घन वटी दो गोली
वयस्क व्यक्ति के लिये यह एक खुराक है /
सभी ऊपर लिखी गयी दवओ की गोलियो को गुन्गुने पानी से तीन तीन घन्टे के अन्तर से खिलाना चाहिये three hourly a with lukwarm water
कम उम्र के किशोरो को ऊपर लिखी दवाओ की एक एक गोली…
View original post 646 more words
Detailed Requirements concerning the DOE in the Regulatory Submission Dossier: EMA’s and FDA’s Recommendations
The EMA has published together with the FDA a new question & answer (Q&A) paper at the end of 2014. This document answers questions on detailed requirements in connection with the documents concerning regulatory submissions. Among others it contains the answer to the question “What level of detail should be considered for design of experiments (DOEs) in a regulatory submission?”
GMP News
25/02/2015
In our News dated 18 February we reported on a question & answer (Q&A) paper which was published by EMA and FDA together at the end of 2014. This document answers questions on detailed requirements in connection with the documents concerning regulatory submissions. It also answers a question on the topic design of experiments (DOE).
The document answers the question “What level of detail should be considered for design of experiments (DOEs) in a regulatory submission?” as follows:
The level of detail should be commensurate…
View original post 165 more words
DR ANTHONY MELVIN CRASTO
ORGANIC SPECTROSCOPY
New Drug Approvals 