Patents by Inventor Hai-Ren Zhang

Hai-Ren Zhang 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: 20110245484
    Abstract: Disclosed herein are phosphorus-containing actives, their use as actives for treating diseases, and a stereoselective process for preparing the same. Also disclosed herein are useful synthetic intermediates and processes for preparing the same.
    Type: Application
    Filed: March 31, 2011
    Publication date: October 6, 2011
    Applicant: PHARMASSET, INC.
    Inventors: BRUCE S. ROSS, MICHAEL JOSEPH SOFIA, GANAPATI REDDY PAMULAPATI, SUGUNA RACHAKONDA, HAI-REN ZHANG
  • Publication number: 20100298257
    Abstract: Disclosed herein are nucleoside phosphoramidates and their use as agents for treating viral diseases. These compounds are inhibitors of RNA-dependent 5 RNA viral replication and are useful as inhibitors of HCV NS5B polymerase, as inhibitors of HCV replication and for treatment of hepatitis C infection in mammals.
    Type: Application
    Filed: May 20, 2010
    Publication date: November 25, 2010
    Applicant: PHARMASSET, INC.
    Inventors: BRUCE ROSS, MICHAEL JOSEPH SOFIA, GANAPATI REDDY PAMULAPATI, SUGUNA RACHAKONDA, HAI-REN ZHANG, BYOUNG-KWON CHUN, PEIYUAN WANG
  • Publication number: 20100279973
    Abstract: A process for preparing phosphoramidate prodrugs or cyclic phosphate prodrugs of nucleoside derivatives, which is a compound, its stereoisomers, salts (acid or basic addition salts), hydrates, solvates, or crystalline forms thereof.
    Type: Application
    Filed: December 23, 2009
    Publication date: November 4, 2010
    Applicant: PHARMASSET, INC.
    Inventors: BYOUNG-KWON CHUN, JINFA DU, SUGUNA RACHAKONDA, BRUCE ROSS, MICHAEL JOSEPH SOFIA, GANAPATI REDDY PAMULAPATI, WONSUK CHANG, HAI-REN ZHANG, DHANAPALAN NAGARATHNAM
  • Publication number: 20090012288
    Abstract: In a process for preparing pentostatin, the improvement wherein reduction is performed on ketone prior to deprotection, comprising: a) reacting 3-(2-deoxy-3,5-di-O-p-toluoyl-b-D-erythro-pentofuranosyl)-6,7-dihydroimidazol [4,5-d][1,3] diazepin-8 (3H)-one with a ruthenium catalyst formed by the reaction of di-?-chlorobis[(p-cymene) chlororuthenium (II) and N-(arylsulfonyl)-1,2-diarylethylene diamine in a solvent; b) stopping the reaction in step a) by making the reaction medium alkaline; c) separating the mixture from step b) into combined organic layers and washing the reaction product from the combined organic layers with water, filtering, and evaporating solvent to provide a crude product, wherein the ratio of 8R vs 8S isomeric alcohol >100; d) purifying said crude product by chromatography; e) deprotecting the keto nucleoside in the crude product in methanol/sodium methoxide to obtain pentostatin; and f) purifying by recrystallizing pentostatin from methanol to remove inorganic and isomeric impurities.
    Type: Application
    Filed: July 3, 2007
    Publication date: January 8, 2009
    Inventors: Hai-Ren Zhang, Wuyi Wang