Patents by Inventor Zhi-Xian Wang

Zhi-Xian Wang 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).

  • Publication number: 20170056424
    Abstract: The present invention relates to solid forms of tenofovir and methods for preparation, use and isolation of such forms.
    Type: Application
    Filed: October 5, 2016
    Publication date: March 2, 2017
    Inventors: Paul Bernard HURLEY, Olga Viktorovna LAPINA, Bing SHI, Fang WANG, Zhi Xian WANG, Jacqueline Ching-See WOO
  • Patent number: 9487546
    Abstract: The present invention relates to solid forms of tenofovir and methods for preparation, use and isolation of such forms.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: November 8, 2016
    Assignee: GILEAD SCIENCES, INC.
    Inventors: Paul Bernard Hurley, Olga Viktorovna Lapina, Bing Shi, Fang Wang, Zhi Xian Wang, Jacqueline Ching-See Woo
  • Publication number: 20150197535
    Abstract: The present invention relates to solid forms of tenofovir and methods for preparation, use and isolation of such forms.
    Type: Application
    Filed: January 9, 2015
    Publication date: July 16, 2015
    Inventors: Paul Bernard Hurley, Olga Viktorovna Lapina, Bing Shi, Fang Wang, Zhi Xian Wang, Jacqueline Ching-See Woo
  • Patent number: 8378143
    Abstract: The present invention provides a process for the preparation of Efavirenz. A compound of Formula 1: may be prepared by a process comprising cyclizing, in the presence of a first base, a compound of Formula 5 with a haloformate of Formula 6. Other processes are also provided as well as novel compounds prepared by and used in such processes.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: February 19, 2013
    Assignee: Apotex Pharmachem Inc.
    Inventors: Bo Chen, Zhi-Xian Wang, Yutao Xue, Lihong Liu, Hao Chen
  • Publication number: 20120095249
    Abstract: The present invention provides a process for the preparation of Efavirenz. A compound of Formula 1: may be prepared by a process comprising cyclizing, in the presence of a first base, a compound of Formula 5 with a haloformate of Formula 6. Other processes are also provided as well as novel compounds prepared by and used in such processes.
    Type: Application
    Filed: December 19, 2011
    Publication date: April 19, 2012
    Applicant: APOTEX PHARMACHEM INC.
    Inventors: Bo CHEN, Zhi-Xian WANG, Yutao XUE, Lihong LIU, Hao CHEN
  • Patent number: 8143400
    Abstract: An industrially acceptable process for the preparation and purification of cis-2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine from a cis/trans mixture of isomers. Treatment of the mixture with an organic sulfonic acid generates a less soluble acid addition salt that is enriched in the cis-isomer. Recrystallization or pulping using various organic solvents allows for enrichment of the cis-isomer by filtration. These new sulfonic acid salts of the cis-isomer of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine prepared according to the present invention could be further converted into the hydrochloride salt by any known procedures such as treatment with a base and then hydrochloric acid salt formation or exchange of the sulfonic acid salt with hydrochloric acid.
    Type: Grant
    Filed: January 10, 2008
    Date of Patent: March 27, 2012
    Assignee: Apotex Pharmachem Inc.
    Inventors: Svetoslav S. Bratovanov, Elena Bejan, David A. Stradiotto, Abbulu Kante, Zhi-Xian Wang, Stephen E. Horne
  • Patent number: 8080663
    Abstract: An industrially acceptable process for the preparation of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine. The cis-isomer of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine is known generally as Cevimeline.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: December 20, 2011
    Assignee: Apotex Pharmachem Inc
    Inventors: Svetoslav S. Bratovanov, Elena Bejan, Zhi-Xian Wang, Stephen E. Horne
  • Patent number: 8080655
    Abstract: The present invention provides a process for the preparation of Efavirenz. A compound of Formula 1: may be prepared by a process comprising cyclizing, in the presence of a first base, a compound of Formula 5 with a haloformate of Formula 6. Other processes are also provided as well as novel compounds prepared by and used in such processes.
    Type: Grant
    Filed: July 20, 2009
    Date of Patent: December 20, 2011
    Assignee: Apotex Pharmachem Inc.
    Inventors: Bo Chen, Zhi-Xian Wang, Yutao Xue, Lihong Liu, Hao Chen
  • Patent number: 7939665
    Abstract: This invention relates to a new and efficient process for the production of dopamine agonists such as Cabergoline and the intermediates thereof.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: May 10, 2011
    Assignee: Apotex Pharmachem Inc.
    Inventors: Zhi-Xian Wang, YuanQiang Li, Murali Kondamreddy, Xiongwei Cai
  • Patent number: 7902380
    Abstract: A process provided for the preparation of the (S)- and (R)- alpha- ethyl-2-oxo-1-pyrrolidineacetamide of formula:(1) from (RS)-alpha-ethyl-2-oxo-1-pyrrolidineacetic acid of formula:(2) comprising: i) combining the (RS)-2 with a chiral base (resolving agent) in a resolution solvent and crystallizing from the said mixture the diastereomeric salt of (S)- or (R)-2 and chiral base; ii) regenerating (S)- or (R)-2 from the crystallized diastereomeric salt by treating with a suitable acid or acidic ion-exchange resin; iii) optionally regenerating (R)- or (S)-2 or their mixture (predominantly one enantiomer) from the crystallization mother liquor by treating with a suitable acid or acidic ion-exchange resin; iv) optionally epimerizing (RS)-2 by treating (R)- or (S)-2 or their mixture (predominantly one enantiomer) of step iii with an acid anhydride; V) optionally converting (RS)-2 of step iv into enantiomerically enriched (S)- or (R)-2 through steps i and ii; vi) formation of the mixed anhydride by reacting (R)- or (S
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: March 8, 2011
    Assignee: Apotex Pharmachem Inc.
    Inventors: Yuan Qiang Li, Zhi-Xian Wang, Bhaskar Reddy Guntoori
  • Patent number: 7884121
    Abstract: This invention relates to a process for the preparation of an aminoalkyl phenyl carbamate compound of formula 1, wherein R1 and R2 independently are hydrogen or C1-6 alkyl; R3 and R4 are the same or different and each is a lower alkyl; or R3 and R4 together with the nitrogen to which they are attached form a cyclic moiety of a three to eight-member ring, with or without a hetero atom like nitrogen or oxygen; R5 and R6 independently are hydrogen, linear, branched or cyclic C1-6 alkyl, allyl, propargyl or benzyl; or R5 and R6 together with the nitrogen to which they are attached form a cyclic moiety of three to eight member ring, with or without a hetero atom like nitrogen or oxygen; the carbon center marked with “*” is racemic or enantiomerically enriched (R)- or (S)-configuration; and pharmaceutically acceptable addition salts, and crystalline and amorphous forms thereof comprising the steps of: i) converting an amine R5R6NH to a carbamoylimidazolium salt of formula 3 wherein R5 and R6 are
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: February 8, 2011
    Assignee: Apotex Pharmachem Inc.
    Inventors: Mohammed Abdul Raheem, Zhi-Xian Wang, Eckardt C. G. Wolf
  • Publication number: 20110015189
    Abstract: The present invention provides a process for the preparation of Efavirenz. A compound of Formula 1 may be prepared by a process comprising cyclizing, in the presence of a first base, a compound of Formula 5 with a haloformate of Formula 6. Other processes are also provided as well as novel compounds prepared by and used in such processes.
    Type: Application
    Filed: July 20, 2009
    Publication date: January 20, 2011
    Applicant: APOTEX PHARMACHEM INC.
    Inventors: Bo CHEN, Zhi-Xian WANG, Yutao XUE, Lihong LIU, Hao CHEN
  • Patent number: 7767843
    Abstract: A process for the preparation of aminoalkyl phenyl carbamate compounds of Formula I, wherein R1 and R2 independently are hydrogen or a C1-6 alkyl; R3 and R4 are the same or different and each is a C1-6 alkyl; or R3 and R4 together with the nitrogen to which they are attached form a cyclic three to eight membered ring, with or without a heteroatom like nitrogen or oxygen; R5 and R6 independently are hydrogen, linear, branched or cyclic C1-6 alkyl; or R5 and R6 together with the nitrogen to which they are attached form a cyclic three to eight membered ring, with or without a heteroatom like nitrogen or oxygen; the carbon centre designated “*” can be racemic or enantiomerically enriched in the (R)- or (S)- configuration; and pharmaceutically acceptable acid addition salts thereof.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: August 3, 2010
    Assignee: Apotex Pharmachem Inc.
    Inventors: Zhi-Xian Wang, Stephen E. Horne, K. S. Keshava Murthy
  • Publication number: 20090182146
    Abstract: An industrially acceptable process for the preparation and purification of cis-2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine from a cisitrans mixture of isomers. Treatment of the mixture with an organic sulfonice acid generates a less soluble acid addition salt that is enriched in the cis-isomer. Recrystallization or pulping using various organic solvents allows for enrichment of the cis-isomer by filtration. These new sulfonic acid salts of the cis-isomer of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine prepared according to the present invention could be further converted into the hydrochloride salt by any known procedures such as treatment with a base and then hydrochloric acid salt formation or exchange of the sulfonic acid salt with hydrochloric acid.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 16, 2009
    Inventors: Svetoslav S. Bratovanov, Elena Bejan, David A. Stradiotto, Abbulu Kante, Zhi-Xian Wang, Stephen E. Horne
  • Patent number: 7531658
    Abstract: The present invention relates to a process for producing 17-N-substituted-carbamoyl-4-aza-androst-1-en-3-ones of formula 1, including Finasteride and Dutasteride.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: May 12, 2009
    Assignee: Apotex Pharmachem Inc.
    Inventors: Zhi-Xian Wang, Alfredo Paul Ceccarelli, Mohammed Abdul Raheem, Bhaskar Reddy Guntoori
  • Publication number: 20090069575
    Abstract: A process provided for the preparation of the (S)— and (R)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide of formula:(1) from (RS)-alpha-ethyl-2-oxo-1-pyrrolidineacetic acid of formula:(2) comprising: i) combining the (RS)-2 with a chiral base (resolving agent) in a resolution solvent and crystallizing from the said mixture the diastereomeric salt of (S)— or (R)-2 and chiral base; ii) regenerating (S)— or (R)-2 from the crystallized diastereomeric salt by treating with a suitable acid or acidic ion-exchange resin; iii) optionally regenerating (R)— or (S)-2 or their mixture (predominantly one enantiomer) from the crystallization mother liquor by treating with a suitable acid or acidic ion-exchange resin; iv) optionally epimerizing (RS)-2 by treating (R)— or (S)-2 or their mixture (predominantly one enantiomer) of step iii with an acid anhydride; V) optionally converting (RS)-2 of step iv into enantiomerically enriched (S)— or (R)-2 through steps i and ii; vi) formation of the mixed anhydride by reacting (R)— or (S)-
    Type: Application
    Filed: November 21, 2005
    Publication date: March 12, 2009
    Inventors: Yuan Qiang Li, Zhi-Xian Wang, Bhaskar Reddy Guntoori
  • Patent number: 7485754
    Abstract: Provided is an efficient method for the preparation of 3-aryloxy-3-arylpropylamines, their optical stereoisomers, and pharmaceutically acceptable salts thereof. The process allows for the isolation of 3-aryloxy-3-arylpropylamines in high yield and purity. The present invention further relates to a process for producing fluoxetine, tomoxetine, norfluoxetine, duloxetine, nisoxetine, and their optically enriched (R)- and (S)-enantiomers.
    Type: Grant
    Filed: July 8, 2005
    Date of Patent: February 3, 2009
    Assignee: Apotex Pharmachem Inc.
    Inventors: Zhi-Xian Wang, Mohammed Abdul Raheem, Gamini Weeratunga, Bhaskar Reddy Guntoori
  • Publication number: 20080306280
    Abstract: This invention relates to a process for the preparation of an aminoalkyl phenyl carbamate compound of formula 1, wherein R1 and R2 independently are hydrogen or C1-6 alkyl; R3 and R4 are the same or different and each is a lower alkyl; or R3 and R4 together with the nitrogen to which they are attached form a cyclic moiety of a three to eight-member ring, with or without a hetero atom like nitrogen or oxygen; R5 and R6 independently are hydrogen, linear, branched or cyclic C1-6 alkyl, allyl, propargyl or benzyl; or R5 and R6 together with the nitrogen to which they are attached form a cyclic moiety of three to eight member ring, with or without a hetero atom like nitrogen or oxygen; the carbon center marked with “*” is racemic or enantiomerically enriched (R)- or (S)-configuration; and pharmaceutically acceptable addition salts, and crystalline and amorphous forms thereof comprising the steps of: i) converting an amine R5R6NH to a carbamoylimidazolium salt of formula 3 wherein R5 and R6 are
    Type: Application
    Filed: June 11, 2007
    Publication date: December 11, 2008
    Inventors: Mohammed Abdul Raheem, Zhi-Xian Wang, Eckardt C.G. Wolf
  • Publication number: 20080275240
    Abstract: This invention relates to a new and efficient process for the production of dopamine agonists such as Cabergoline and the intermediates thereof.
    Type: Application
    Filed: May 4, 2007
    Publication date: November 6, 2008
    Inventors: Zhi-Xian Wang, YuanQiang Li, Murali Kondamreddy, Xiongwei Cai
  • Publication number: 20080249312
    Abstract: An industrially acceptable process for the preparation of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine. The cis-isomer of 2-methylspiro(1,3-oxathiolane-5,3?)quiniclidine is known generally as Cevimeline.
    Type: Application
    Filed: April 4, 2007
    Publication date: October 9, 2008
    Inventors: Svetoslav S. Bratovanov, Elena Bejan, Zhi-Xian Wang, Stephen E. Horne