Patents by Inventor Daqing Che

Daqing Che has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7863442
    Abstract: There is provided a process for the preparation of olanzapine comprising: i) reacting 4-amino-2-methyl-10H-thieno-[2,3-b][1,5]benzodiazepine and N-methylpiperazine in a C1 to C4 alcoholic solvent or mixture thereof at suitable temperature and for a suitable time, ii) cooling the reaction mixture, and iii) isolating the precipitated olanzapine.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: January 4, 2011
    Assignee: Apotex Pharmachem Inc.
    Inventors: Kiran Kumar Kothakonda, Daqing Che, Bhaskar Reddy Guntoori
  • Publication number: 20100324298
    Abstract: A novel process for the preparation of omeprazole and its enantiomers, such as esomeprazole, as well as the preparation of related 2-(2-pyridinylmethyl-sulphinyl)-1H-benzimidazoles, including pantoprazole, lansoprazole and rabeprazole, as recemates or single enantiomers, and their alkali or alkaline salts has been developed. The novel process involves the surprising discovery that protection of the free-base benzimidazole sulfoxide (e.g. omeprazole or esomeprazole), by reaction with an alkyl, aryl or aralkyl chloroformate following oxidation of the corresponding sulfide, eliminates the need for its direct isolation. Subsequent removal of the protecting group with a solution of alkali or alkaline earth alkoxide in a C1-C4 alcohol directly provides the corresponding salt. By eliminating the need to handle the free-base benzimidazole sulfoxide, this advantageous procedure provides increased chemical yields over processes described in the art.
    Type: Application
    Filed: August 12, 2010
    Publication date: December 23, 2010
    Applicant: APOTEX PHARMACHEM INC.
    Inventors: Fan Wang, Laura Kaye Montemayor, Daqing Che, Stephen E. Horne
  • Patent number: 7834195
    Abstract: Atorvastatin calcium propylene glycol solvates and processes to prepare these novel solvates which are particularly useful and suitable for pharmaceutical applications.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: November 16, 2010
    Assignee: Apotex Pharmachem Inc.
    Inventors: K. S. Keshava Murthy, Yajun Zhao, Allan W. Rey, Daqing Che, David A. Stradiotto, Uma Kotipalli
  • Patent number: 7812179
    Abstract: A process is provided for preparing (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, R-substituted ester 9 comprising: (a) reacting the aldehyde 1 with the enolate form of (S)-2-hydroxy-1,2,2-triphenylethyl acetate substituent in a chelating co-solvent; (b) hydrolysis of (R,S)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-hydroxy-1-pentanoic acid, (S)-2-hydroxy-1,2,2-triphenylethyl ester (2a and 2b) using a base, preferably an alkali metal base, preferably in a solvent to form the carboxylic acid 7; (c) treating the acid 7 with a chiral base to form a salt and purifying the salt to obtain enantiomerically enriched (R)-7 chiral base salt; (d) alkylation of the (R)-7 chiral base salt or the free base derived from (R)-7, forming (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid,
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: October 12, 2010
    Assignee: Apotex PharmaChem Inc.
    Inventors: Fan Wang, Daqing Che, Bhaskar Reddy Guntoori, Yajun Zhao, Aaron C. Kinsman, Jody Faught, Alan Chow
  • Patent number: 7786309
    Abstract: A novel process for the preparation of omeprazole and its enantiomers, such as esomeprazole, as well as the preparation of related 2-(2-pyridinylmethyl-sulphinyl)-1H-benzimidazoles, including pantoprazole, lansoprazole and rabeprazole, as recemates or single enantiomers, and their alkali or alkaline salts has been developed. The novel process involves the surprising discovery that protection of the free-base benzimidazole sulfoxide (e.g. omeprazole or esomeprazole), by reaction with an alkyl, aryl or aralkyl chloroformate following oxidation of the corresponding sulfide, eliminates the need for its direct isolation. Subsequent removal of the protecting group with a solution of alkali or alkaline earth alkoxide in a C1-C4 alcohol directly provides the corresponding salt. By eliminating the need to handle the free-base benzimidazole sulfoxide, this advantageous procedure provides increased chemical yields over processes described in the art.
    Type: Grant
    Filed: May 9, 2007
    Date of Patent: August 31, 2010
    Assignee: Apotex Pharmachem Inc.
    Inventors: Fan Wang, Laura Kaye Montemayor, Daqing Che, Stephen E. Horne
  • Patent number: 7709634
    Abstract: A stable amorphous form of rifaximin is disclosed. This form is chemically and polymorphically stable on storage and can be prepared by dissolving rifaximin in a solvent to form a solution, which is precipitated by adding an anti-solvent and isolating of the precipitated amorphous rifaximin as an end product.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: May 4, 2010
    Assignee: Apotex PharmAchem Inc.
    Inventors: Kiran Kumar Kothakonda, Daqing Che
  • Patent number: 7615647
    Abstract: A process is provided for preparing pharmaceutical grade atorvastatin hemicalcium salt comprising: (a) deesterifying, wherein R is an ester protecting group to (b) extracting R(R*,R*)-3 into an organic solvent or mixture of solvents, (c) adding a base of formula NR1R2R3 wherein R1, R2 and R3 are independently selected from H, substituted or non-substituted C1 to C7 alkyl, C6 to C9 aryl, C8 to C10 aralkyl or aminoalkyl to form atorvastatin base salt, (d) isolating by precipitation of the above atorvastatin base salt and purifying when necessary, (e) converting atorvastatin base salt to atorvastatin hemicalcium salt by treatment with a calcium salt solution, and (f) isolating the atorvastatin hemicalcium salt.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: November 10, 2009
    Assignee: Apotex Pharmachem Inc.
    Inventors: K.S. Keshava Murthy, Yajun Zhao, Daqing Che, Bhaskar Reddy Guntoori, Sammy Chris Duncan, Stephen E. Horne
  • Publication number: 20090247749
    Abstract: The present invention is directed to novel crystalline forms of adefovir dipivoxil and salts thereof.
    Type: Application
    Filed: March 31, 2008
    Publication date: October 1, 2009
    Inventors: Peter Garth Blazecka, Daqing Che, Cameron L. McPhail, Allan W. Rey
  • Publication number: 20090131683
    Abstract: A process is provided for preparing (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, R-substituted ester 9 comprising: (a) reacting the aldehyde 1 with the enolate form of (S)-2-hydroxy-1,2,2-triphenylethyl acetate substituent in a chelating co-solvent; (b) hydrolysis of (R,S)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-hydroxy-1-pentanoic acid, (S)-2-hydroxy-1,2,2-triphenylethyl ester (2a and 2b) using a base, preferably an alkali metal base, preferably in a solvent to form the carboxylic acid 7; (c) treating the acid 7 with a chiral base to form a salt and purifying the salt to obtain enantiomerically enriched (R)-7 chiral base salt; (d) alkylation of the (R)-7 chiral base salt or the free base derived from (R)-7, forming (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid,
    Type: Application
    Filed: August 14, 2008
    Publication date: May 21, 2009
    Inventors: Fan Wang, Daqing Che, Bhaskar Reddy Guntoori, Yajun Zhao, Aaron C. Kinsman, Jody Faught, Alan Chow
  • Publication number: 20090082558
    Abstract: A stable amorphous form of rifaximin is disclosed. This form is chemically and polymorphically stable on storage and can be prepared by dissolving rifaximin in a solvent to form a solution, which is precipitated by adding an anti-solvent and isolating of the precipitated amorphous rifaximin as an end product.
    Type: Application
    Filed: September 20, 2007
    Publication date: March 26, 2009
    Inventors: Kiran Kumar Kothakonda, Daqing Che
  • Publication number: 20090023955
    Abstract: The present invention relates to novel processes to produce sertraline hydrochloride Form II comprising the steps of forming a solution of sertraline hydrochloride in a polar organic solvent and adding this solution to a less polar organic solvent.
    Type: Application
    Filed: October 25, 2007
    Publication date: January 22, 2009
    Inventors: Daqing Che, Fan Wang, Shahid Rabbani
  • Publication number: 20080319189
    Abstract: There is provided a process for the preparation of olanzapine comprising: i) reacting 4-amino-2-methyl-10H-thieno-[2,3-b][1,5]benzodiazepine and N-methylpiperazine in a C1 to C4 alcoholic solvent or mixture thereof at suitable temperature and for a suitable time, ii) cooling the reaction mixture, and iii) isolating the precipitated olanzapine.
    Type: Application
    Filed: October 30, 2007
    Publication date: December 25, 2008
    Inventors: Kiran Kumar Kothakonda, Daqing Che, Bhaskar Reddy Guntoori
  • Publication number: 20080312433
    Abstract: A process for obtaining crystalline Form-I olanzapine comprising the following: a) dissolving crude olanzapine in a solvent to form a solution, b) optionally drying by azeotropic distillation to remove water, c) precipitating by adding the solution of step (a) to an antisolvent, and d) isolating the precipitated crystalline Form-I olanzapine by filtration and drying at ambient temperature.
    Type: Application
    Filed: October 30, 2007
    Publication date: December 18, 2008
    Inventors: Daqing Che, Kiran Kumar Kothakonda, Cameron L. McPhail, Bhaskar Reddy Guntoori
  • Patent number: 7429613
    Abstract: A process is provided for preparing (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, R-substituted ester 9 comprising: (a) reacting the aldehyde 1 with the enolate form of (S)-2-hydroxy-1,2,2-triphenylethyl acetate substituent in a chelating co-solvent; (b) hydrolysis of (R,S)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-hydroxy-1-pentanoic acid, (S)-2-hydroxy-1,2,2-triphenylethyl ester (2a and 2b) using a base, preferably an alkali metal base, preferably in a solvent to form the carboxylic acid 7; (c) treating the acid 7 with a chiral base to form a salt and purifying the salt to obtain enantiomerically enriched (R)-7 chiral base salt; (d) alkylation of the (R)-7 chiral base salt or the free base derived from (R)-7, forming (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid,
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: September 30, 2008
    Assignee: Apotex Pharmachem Inc.
    Inventors: Fan Wang, Daqing Che, Bhaskar Reddy Guntoori, Yajun Zhao, Aaron C. Kinsman, Jody Faught, Alan Chow
  • Publication number: 20080177087
    Abstract: Atorvastatin calcium propylene glycol solvates and processes to prepare these novel solvates which are particularly useful and suitable for pharmaceutical applications.
    Type: Application
    Filed: June 14, 2007
    Publication date: July 24, 2008
    Inventors: K.S. Keshava Murthy, Yajun Zhao, Allan W. Rey, Daqing Che, David A. Stradiotto, Uma Kotipalli
  • Patent number: 7378527
    Abstract: A process for preparing torsemide or salts thereof comprising: a) reacting II with isopropyl isocyanate in the presence of an alkali carbonate or bicarbonate and an organic solvent to form an alkali torsemide mixture, b) recovering the alkali torsemide mixture, and c) if desired, recovering the torsemide by acidification of the alkali torsemide mixture.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: May 27, 2008
    Inventors: Daqing Che, Bhaskar Reddy Guntoori, Sammy Chris Duncan
  • Publication number: 20070287839
    Abstract: A novel process for the preparation of omeprazole and its enantiomers, such as esomeprazole, as well as the preparation of related 2-(2-pyridinylmethyl-sulphinyl)-1H-benzimidazoles, including pantoprazole, lansoprazole and rabeprazole, as recemates or single enantiomers, and their alkali or alkaline salts has been developed. The novel process involves the surprising discovery that protection of the free-base benzimidazole sulfoxide (e.g. omeprazole or esomeprazole), by reaction with an alkyl, aryl or aralkyl chloroformate following oxidation of the corresponding sulfide, eliminates the need for its direct isolation. Subsequent removal of the protecting group with a solution of alkali or alkaline earth alkoxide in a C1-C4 alcohol directly provides the corresponding salt. By eliminating the need to handle the free-base benzimidazole sulfoxide, this advantageous procedure provides increased chemical yields over processes described in the art.
    Type: Application
    Filed: May 9, 2007
    Publication date: December 13, 2007
    Inventors: Fan Wang, Laura Kaye Montemayor, Daqing Che, Stephen E. Home
  • Patent number: 7193090
    Abstract: A process for preparing (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, tert-butylester comprising: (a) reduction of 5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-oxo-1-pentanoic acid, (R)-2-hydroxy-1,2,2-triphenylethyl ester; (b) hydrolysis of (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-hydroxy-1-pentanoic acid, (R)-2-hydroxy-1,2,2-triphenylethyl ester using an alkali base in a solvent to form the acid; (c) alkylation of the acid forming (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, tert-butylester.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: March 20, 2007
    Assignee: Apotex Pharmachem Inc.
    Inventors: Bhaskar Reddy Guntoori, Daqing Che, Fan Wang, Yajun Zhao, K. S. Keshava Murthy, Stephen E. Horne
  • Publication number: 20060252816
    Abstract: A process is provided for preparing (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, R-substituted ester 9 comprising: (a) reacting the aldehyde 1 with the enolate form of (S)-2-hydroxy-1,2,2-triphenylethyl acetate substituent in a chelating co-solvent; (b) hydrolysis of (R,S)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-3-hydroxy-1-pentanoic acid, (S)-2-hydroxy-1,2,2-triphenylethyl ester (2a and 2b) using a base, preferably an alkali metal base, preferably in a solvent to form the carboxylic acid 7; (c) treating the acid 7 with a chiral base to form a salt and purifying the salt to obtain enantiomerically enriched (R)-7 chiral base salt; (d) alkylation of the (R)-7 chiral base salt or the free base derived from (R)-7, forming (R)-5-[2-(4-fluorophenyl)-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrol-1-yl]-5-hydroxy-3-oxo-1-heptanoic acid, R-substituted ester
    Type: Application
    Filed: July 17, 2006
    Publication date: November 9, 2006
    Inventors: Fan Wang, Daqing Che, Bhaskar Guntoori, Yajun Zhao, Aaron Kinsman, Jody Faught, Alan Chow
  • Patent number: 7125987
    Abstract: A process for preparing Oxcarbazepine III comprising: a) reacting oximinostilbene IV ?with chlorosulfonyl isocyanate in an inert organic solvent and isolating compound V b) hydrolyzing compound V to form crude Oxcarbazepine III c) purifying oxcarbazepine.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: October 24, 2006
    Assignee: Apotex Pharmachem Inc.
    Inventors: Daqing Che, Nadia Corelli-Rennie, Bhaskar Reddy Guntoori, Jodi Faught