Patents by Inventor Gerald L. Powers

Gerald L. Powers 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).

  • Process for preparing the antiviral agent [1S-(1alpha,3 alpha,4beta )]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one
    Patent number: 7034152
    Abstract: Processes are disclosed for preparing the antiviral agent entecavir. A resin adsorption process for the isolation and purification of entecavir is also disclosed. Various intermediates useful in the preparation of entecavir are also disclosed.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: April 25, 2006
    Assignee: Bristol-Myers Squibb Company
    Inventors: Yadagiri R. Pendri, Chung-Pin H. Chen, Sunil S. Patel, Jeffrey M. Evans, Jing Liang, David R. Kronenthal, Gerald L. Powers, Siva Josyula Prasad, Jeffrey T. Bien, Zhongping Shi, Ramesh N. Patel, Amit Banerjee, Yeung Yu Chan, Sushil K. Rijhwani, Ambarish K. Singh, Shaopeng Wang, Milan Stojanovic, David J. Kucera, Richard P. Polniaszek, Charles Lewis, John Thottathil, Dhileepkumar Krishnamurty, Maotang X. Zhou, Purushotham Vemishetti
  • Process for preparing the antiviral agent [1S-(1alpha,3 alpha,4beta)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one
    Publication number: 20040192912
    Abstract: Processes are disclosed for preparing the antiviral agent entecavir. A resin adsorption process for the isolation and purification of entecavir is also disclosed. Various intermediates useful in the preparation of entecavir are also disclosed.
    Type: Application
    Filed: December 11, 2003
    Publication date: September 30, 2004
    Inventors: Yadagiri R. Pendri, Chung-Pin H. Chen, Sunil S. Patel, Jeffrey M. Evans, Jing Liang, David R. Kronenthal, Gerald L. Powers, Siva Josyula Prasad, Jeffrey T. Bien, Zhongping Shi, Ramesh N. Patel, Amit Banerjee, Yeung Yu Chan, Sushil K. Rijhwani, Ambarish K. Singh, Shaopeng Wang, Milan Stojanovic, David J. Kucera, Richard P. Polniaszek, Charles Lewis, John Thottathil, Dhileepkumar Krishnamurty, Maotang X. Zhou, Purushotham Vemishetti
  • Preparation of (S)-2-amino-6,6-dimethoxyhexanoic acid methyl ester via novel dioxolanes
    Patent number: 6329542
    Abstract: The glycinamide of the formula is reacted with the dioxolane of the formula wherein L is a leaving group such as iodo, bromo, alkylsulfonyloxy, or arylsulfonyloxy to give the dioxolane of the formula Treating the dioxolane of formula III under aqueous refluxing conditions followed by exchanging the dioxolane acetal with a dimethoxy acetal and introduction of the methyl ester gives (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester which is an intermediate in the preparation of the dual inhibitor [4S-[4&agr;(R*),7&agr;,10a&bgr;]]-octahydro-4-[(2-mercapto-1-oxo-3-phenylpropyl)-amino]-5-oxo-7H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid. Also disclosed are storage stable salts of (S)-2-amino-6, 6-dimethoxyhexanoic acid, methyl ester.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: December 11, 2001
    Assignee: Bristol-Myers Squibb Co.
    Inventors: Jollie D. Godfrey, Jr., David R. Kronenthal, Mark D. Schwinden, Sushil K. Srivastava, Keith Ramig, John J. Venit, Paul A. Jass, Saibaba Racha, John L. Dillon, Jr., Nachimuthu Soundararajan, Gerald L. Powers, Atul S. Kotnis
  • Preparation of (s)-2-amino-6,6-dimethoxyhexanoic acid methyl ester via novel dioxolanes
    Patent number: 6248882
    Abstract: The glycinamide of the formula is reacted with the dioxolane of the formula wherein L is a leaving group such as iodo, bromo, alkylsulfonyloxy, or arylsulfonyloxy to give the dioxolane of the formula Treating the dioxolane of formula III under aqueous refluxing conditions followed by exchanging the dioxolane acetal with a dimethoxy acetal and introduction of the methyl ester gives (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester which is an intermediate in the preparation of the dual inhibitor [4S-[4&agr;(R*),7&agr;, 10a&bgr;]]-)octahydro-4-[(2-mercapto-1-oxo-3-phenylpropy)-amino]-5-oxo-7H-pyrido[2,1-b][1,3]thiazepine-7-carboxylic acid. Also disclosed are storage stable salts of (S)-2-amino-6,6-dimethoxyhexanoic acid, methyl ester.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: June 19, 2001
    Assignee: Bristol-Myers Squibb Co.
    Inventors: Jollie D. Godfrey, Jr., David R. Kronenthal, Mark D. Schwinden, Sushil K. Srivastava, Keith Ramig, John J. Venit, Paul A. Jass, Saibaba Racha, John L. Dillon, Jr., Nachimuthu Soundararajan, Gerald L. Powers, Atul S. Kotnis
  • Reaction conditions for the cleavage of silyl ethers in the preparation of paclitaxel(taxol®) and paclitaxel analogues
    Patent number: 6184395
    Abstract: Novel reaction conditions for the cleavage of silyl ethers from silyl protected taxane precursors to afford paclitaxel and paclitaxel analogues in high yield and quality are described. Paclitaxel is prepared from a taxane precursor by treating the taxane precursor with a strong acid such as trifluoroacetic acid in a solvent such as aqueous acetic acid, such that the amount and number of side reactions and taxane impurities are significantly minimized. Also desribed are the crystallization methods for the isolation of paclitaxel in either of the two crystal forms A or B. Paclitaxel and paclitaxel analogues are anti-cancer agents.
    Type: Grant
    Filed: May 16, 2000
    Date of Patent: February 6, 2001
    Assignee: Bristol-Myers Squibb Company
    Inventors: Ambarish K. Singh, Raymond E. Weaver, Gerald L. Powers, Victor W. Rosso
  • Salts of metformin and method
    Patent number: 6031004
    Abstract: Novel salts of the antidiabetic agent metformin acre provided which are metformin salts of dibasic acids (2:1 molar ratio), preferably metformin (2:1) fumarate and metformin (2:1) succinate, which may be employed alone or in combination with another antihyperglycemic agent such as glyburide, for treating diabetes. A method for treating diabetes employing the novel metformin salt by itself or in combination with another antidiabetic agent is also provided.
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: February 29, 2000
    Assignee: Bristol-Myers Squibb Company
    Inventors: Peter Timmins, William J. Winter, Sushil K. Srivastava, Alison E. Bretnall, Chenkou Wei, Gerald L. Powers