Patents Assigned to Dabur India Limited
  • Patent number: 7759494
    Abstract: 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-s
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: July 20, 2010
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
  • Publication number: 20080064887
    Abstract: 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: Application
    Filed: June 15, 2007
    Publication date: March 13, 2008
    Applicant: DABUR INDIA LIMITED
    Inventors: Arun Sharma, Subrata Sarkar, Jyan Mahanty
  • Patent number: 7247738
    Abstract: 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-su
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: July 24, 2007
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
  • Patent number: 6900342
    Abstract: 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: Grant
    Filed: May 8, 2003
    Date of Patent: May 31, 2005
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shankar Mahanty
  • Patent number: 6891050
    Abstract: A process for the preparation of taxanes including paclitaxel, docetaxel, and structurally similar analogs, as well as intermediates produced by the process.
    Type: Grant
    Filed: August 7, 2002
    Date of Patent: May 10, 2005
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Subrata Sarkar
  • Patent number: 6881852
    Abstract: 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 pure
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: April 19, 2005
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Jyan Shankar Mahanty, Subrata Sarkar
  • Patent number: 6838569
    Abstract: 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: Grant
    Filed: April 22, 2003
    Date of Patent: January 4, 2005
    Assignee: Dabur India Limited
    Inventors: Arun Prakash Sharma, Subrata Sarkar, Jyan Shanker Mahanty
  • Patent number: 6506905
    Abstract: 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: Grant
    Filed: June 1, 2001
    Date of Patent: January 14, 2003
    Assignee: Dabur India Limited
    Inventors: Sharma Arun Prakash, Sarkar Subrata
  • Patent number: D574710
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: August 12, 2008
    Assignee: Dabur India Limited
    Inventor: Hitesh Gangrade