Patents Assigned to Dabur India Limited
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Patent number: 7759494Abstract: This invention relates to a process for preparation of taxanes comprising subjecting 7,10-diprotected intermediates 7-O-(2-haloacyl)baccatin III 6c or 7,10-O-di-(2-haloacyl)-10-deacetylbaccatin III 6b to a step of coupling with (4S,5R)-3-[(2-alkyl/aryl-2-trialkylsilyl)ethoxy-carbonyl]-4-aryl-2-substituted-1,3-oxazolidine-5-carboxylic acid 1 in the presence of a condensation agent, an activating agent and an aromatic hydrocarbon to obtain 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3(2-unsubstituted/substituted-2-trialkylsilyl)-ethoxycarbonyl-1,3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O [2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-unsubstituted/substituted-2-trialkylsilyl)ethoxy-carbonyl-1,3-oxazolidinyl-5-carbonyl]-10-deacetylbaccatin III 7b; treating the coupled products 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-substituted-2-trialkylsilyl)ethoxy-carbonyl-1,3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O-[2[(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-sType: GrantFiled: June 15, 2007Date of Patent: July 20, 2010Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
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Publication number: 20080064887Abstract: This invention relates to a process for preparation of taxanes comprising subjecting 7,10-diprotected intermediates 7-O-(2-haloacyl)baccatin III 6c or 7,10-O-di-(2-haloacyl)-10-deacetylbaccatin III 6b to a step of coupling with (4S,5R)-3-[(2-alkyl/aryl-2-trialkylsilyl)ethoxy-carbonyl]-4-aryl-2-substituted-1,3-oxazolidine-5-carboxylic acid 1 in the presence of a condensation agent, an activating agent and an aromatic hydrocarbon to obtain 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3(2-unsubstituted/substituted-2-trialkylsilyl)-ethoxycarbonyl-1,3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O [2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-unsubstituted/substituted-2-trialkylsilyl)ethoxy-carbonyl-1, 3-oxazolidinyl-5-carbonyl]-10-deacetylbaccatin III 7b; treating the coupled products 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-substituted-2-trialkylsilyl)ethoxy-carbonyl-1, 3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O-[2[(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-Type: ApplicationFiled: June 15, 2007Publication date: March 13, 2008Applicant: DABUR INDIA LIMITEDInventors: Arun Sharma, Subrata Sarkar, Jyan Mahanty
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Patent number: 7247738Abstract: This invention relates to a process for preparation of taxanes comprising subjecting 7,10-diprotected intermediates 7-O-(2-haloacyl)baccatin III 6c or 7,10-O-di-(2-haloacyl)-10-deacetylbaccatin III 6b to a step of coupling with (4S,5R)-3-[(2-alkyl/aryl-2-trialkylsilyl)ethoxy-carbonyl]-4-aryl-2-substituted-1,3-oxazolidine-5-carboxylic acid 1 in the presence of a condensation agent, an activating agent and an aromatic hydrocarbon to obtain 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3(2-unsubstituted/substituted-2-trialkylsilyl)-ethoxycarbonyl-1,3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-unsubstituted/substituted-2-trialkylsilyl)ethoxy-carbonyl-1,3-oxazolidinyl-5-carbonyl]-10-deacetylbaccatin III 7b; treating the coupled products 7-O-[2-(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-substituted-2-trialkylsilyl)ethoxy-carbonyl-1,3-oxazolidinyl-5-carbonyl]baccatin III 7a or 7,10-di-O-[2[(haloacyl)]-13-[(4S,5R)-4-aryl-2-substituted-3-(2-suType: GrantFiled: May 7, 2003Date of Patent: July 24, 2007Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
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Patent number: 6900342Abstract: A process for the preparation of taxanes comprising wherein R is a tert. butoxycarbonyl or benzoyl group; PMP is p-methoxyphenyl group; G1 is acetyl group; G2 is haloacetyl group comprising a) protecting the C-7 hydroxyl group of 10-deacetylbaccatin III with haloacetyl chlorides and then acetylating the C-10 hydroxyl group with acetyl chloride to obtain a protected 10-deacetylbaccatin III (1); b) subjecting the protected 10-deacetylbaccatin III (1) to coupling with an oxazolidine-5-caboxylic acid of formula 2 wherein R is tert. butoxycarbonyl or benzoyl; PMP is p-methoxyphenyl group in the presence of a condensation agent and an activating agent to obtain C-13 esters of formula 3; c) treating the coupled products 3 with weak acidic medium to open the oxazolidine ring to obtain intermediates of formula 4; wherein R is a tert.Type: GrantFiled: May 8, 2003Date of Patent: May 31, 2005Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
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Patent number: 6891050Abstract: A process for the preparation of taxanes including paclitaxel, docetaxel, and structurally similar analogs, as well as intermediates produced by the process.Type: GrantFiled: August 7, 2002Date of Patent: May 10, 2005Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Subrata Sarkar
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Patent number: 6881852Abstract: A process for the purification of paclitaxel or docetaxel comprising: (a) mixing crude paclitaxel with a mixture of solvents such as alkane and chlorinated alkane, filtering the solid followed by drying to obtain paclitaxel or docetaxel of increased purity; (b) repeating step (a) one or more times to obtain paclitaxel or docetaxel of increased purity; (c) dissolving the solid obtained from step (b) in alkyl ketone followed by adding alkane thereto, filtering and drying the solid thus formed to obtain paclitaxel or docetaxel of increased purity; (d) repeating step (c) one or more times to increase the purity of paclitaxel or docetaxel; (e) dissolving the paclitaxel or docetaxel obtained from step (d) in alkanol and then adding water, filtering and drying the solid thus formed, to obtain paclitaxel of increased purity; (f) dissolving the solid obtained from step (e) in alkyl ketone, filtering, followed by adding alkane to the filtrate, filtering and drying the solid thus formed to obtain pure paclitaxel or pureType: GrantFiled: February 5, 2003Date of Patent: April 19, 2005Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Jyan Shankar Mahanty, Subrata Sarkar
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Patent number: 6838569Abstract: A process for converting paclitaxel or docetaxel to the respective trihydrate characterized by very high purity, comprises dissolving either paclitaxel or docetaxel in a mixture of alkane and chlorinated alkane to provide a crude product of 65-75% assay and dissolving the crude product in an alkyl ketone, followed by addition of an alkane to provide a product of increased chromatographic purity; dissolving the product of increased chromatographic purity in an aliphatic nitrile, with addition of water to precipitate taxane trihydrate.Type: GrantFiled: April 22, 2003Date of Patent: January 4, 2005Assignee: Dabur India LimitedInventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shanker Mahanty
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Patent number: 6506905Abstract: 3-(alk-2-ynyloxy)carbonyl-5-oxazolidine carboxylic acid and its analogs having a formula and wherein R1 is hydrogen, aryl, heteroaryl, alkyl, alkenyl, alkynyl, R2 and R3 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, R4 is hydrogen, alkyl, alkenyl, alkynyl, aryl, substituted aryl, heteroaryl, R5 and R6 independently selected from hydrogen, alkyl, alkenyl,alkynyl, arly, heteroaryl, alkoxy, alkeyloxy, alkynyloxy, aryloxy, heteroaryloxy.Type: GrantFiled: June 1, 2001Date of Patent: January 14, 2003Assignee: Dabur India LimitedInventors: Sharma Arun Prakash, Sarkar Subrata
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Patent number: D574710Type: GrantFiled: September 14, 2007Date of Patent: August 12, 2008Assignee: Dabur India LimitedInventor: Hitesh Gangrade