Patents by Inventor Ambarish K. Singh

Ambarish K. Singh 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).

  • Intermediates in the preparation of entecavir via carbon-silicon oxidation
    Patent number: 7968555
    Abstract: Processes for preparing entecavir and novel intermediates thereof using carbon-silicon oxidation.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: June 28, 2011
    Assignee: Bristol-Myers Squibb Company
    Inventors: Maotang X. Zhou, Emily A. Reiff, Purushotham Vemishetti, Yadagiri R. Pendri, Ambarish K. Singh, Siva Josyula Prasad, Ulhas P. Dhokte, Xinhua Qian, Pia Mountford, Kerry B. Hartung, Helen Sailes
  • Process for the Preparation of Entecavir and Novel Intermediates Thereof Via Carbon-Silicon Oxidation
    Publication number: 20100286089
    Abstract: Processes for preparing entecavir and novel intermediates thereof using carbon-silicon oxidation.
    Type: Application
    Filed: July 22, 2010
    Publication date: November 11, 2010
    Inventors: Maotang X. Zhou, Emily A. Reiff, Purushotham Vemishetti, Yadagiri R. Pendri, Ambarish K. Singh, Siva Josyula Prasad, Ulhas P. Dhokte, Xinhua Qian, Pia Mountford, Kerry B. Hartung, Helen Sailes
  • Process for preparation of entecavir and novel intermediates thereof via carbon-silicon oxidation
    Patent number: 7786300
    Abstract: Processes for preparing entecavir and novel intermediates thereof using carbon-silicon oxidation.
    Type: Grant
    Filed: February 4, 2009
    Date of Patent: August 31, 2010
    Assignee: Bristol-Myers Squibb Company
    Inventors: Maotang X. Zhou, Emily A. Reiff, Purushotham Vemishetti, Yadagiri R. Pendri, Ambarish K. Singh, Siva Josyula Prasad, Ulhas P. Dhokte, Xinhua Qian, Pia Mountford, Kerry B. Hartung, Helen Sailes
  • Process for Preparation of Entecavir and Novel Intermediates Thereof Via Carbon-Silicon Oxidation
    Publication number: 20090143578
    Abstract: Processes for preparing entecavir and novel intermediates thereof using carbon-silicon oxidation.
    Type: Application
    Filed: February 4, 2009
    Publication date: June 4, 2009
    Inventors: Maotang X. Zhou, Emily A. Reiff, Purushotham Vemishetti, Yadagiri R. Pendri, Ambarish K. Singh, Siva Josyula Prasad, Ulhas P. Dhokte, Xinhua Qian, Pia Mountford, Kerry B. Hartung, Helen Sailes
  • Process for the preparation of entecavir and novel intermediates thereof via carbon-silicon oxidation
    Patent number: 7511139
    Abstract: Processes for preparing entecavir and novel intermediates thereof using carbon-silicon oxidation.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: March 31, 2009
    Assignee: Bristol-Myers Squibb Company
    Inventors: Maotang X. Zhou, Emily A. Reiff, Purushotham Vemishetti, Yadagiri R. Pendri, Ambarish K. Singh, Siva Josyula Prasad, Ulhas P. Dhokte, Xinhua Qian, Pia Mountford, Kerry B. Hartung, Helen Sailes
  • 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
  • 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