Patents Assigned to Pharmasset, Ltd.
  • 3?-or 2?-hydroxymethyl substituted nucleoside derivatives for treatment of hepatitis virus infections
    Patent number: 7094770
    Abstract: The present invention relates to a composition for and a method of treating hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, hepatitis D virus (HDV) infection or a proliferative disorder in a patient using an effective amount of a compound selected from the group consisting of formulas [I]–[IV] below and mixtures of two or more thereof: wherein the substituents are as defined herein. Pharmaceutical compositions comprising these compounds in combination with other HBV, HCV, or HDV agents is also disclosed.
    Type: Grant
    Filed: April 13, 2001
    Date of Patent: August 22, 2006
    Assignee: Pharmasset, Ltd.
    Inventors: Kyoichi A. Watanabe, S. Balakrishna Pai
  • Method for the synthesis of 2?,3?-dideoxy-2?,3?-didehydronucleosides
    Patent number: 6927291
    Abstract: An efficient synthetic route to antiviral 2?,3?-dideoxy-2?,3?-didehydro-nucleosides, such as 2?,3?-dideoxy and 2?- or 3?-deoxyribo-nucleoside analogs, from available precursors is disclosed, with the option of introducing functionality as needed. In one embodiment, a method for the preparation of ?-D and ?-L-2?,3?-dideoxy-2?,3?-didehydro-nucleosides is described that includes: activating a compound of structure (1) wherein B is a pyrimidine or purine base and Y is O, S or CH2 with an acyl halide of the formula X—C(?O)R1, X—C(?O)C(R1)2OC(?O)R1 or X—C(?O)OR1 (wherein X is a halogen, and each R1 is independently hydrogen, lower alkyl, alkyl, aryl or phenyl); reducing the resulting compound with a reducing agent to form a 2?,3?-dideoxy-2?,3?-didehydro-nucleoside; and optionally deprotecting the nucleoside. The haloacylation of the first step can form the 2?-acyl-3?-halonucleoside, the 3?-acyl-2?-halonucleoside, or a mixture thereof.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: August 9, 2005
    Assignee: Pharmasset, Ltd.
    Inventors: Fuqiang Jin, Pasquale N. Confalone
  • Processes for preparing 1,3-dioxolane nucleosides
    Patent number: 6855821
    Abstract: Disclosed are novel processes for preparing 1,3-dioxolane nucleosides of general formula I and II: wherein B is a purine or pyrimidine base or an analog or derivative thereof. The invention also provides intermediates for use in the preparation of these compounds.
    Type: Grant
    Filed: August 6, 2003
    Date of Patent: February 15, 2005
    Assignee: Pharmasset, Ltd.
    Inventors: Jinfa Du, Kyoichi A. Watanabe
  • Tetraphosphonate bicyclic trisanhydrides
    Publication number: 20040181078
    Abstract: Disclosed are novel bicyclic tris(anhydride)s useful as intermediates in the synthesis of biologically active compounds, and the compounds which may be synthesized from such intermediates.
    Type: Application
    Filed: March 29, 2004
    Publication date: September 16, 2004
    Applicant: Pharmasset, Ltd.
    Inventors: Krzysztof W. Pankiewicz, Krystyna Lesiak, Kyoichi A. Watanabe
  • Tetraphosphonate bicyclic trisanhydrides
    Patent number: 6713623
    Abstract: Disclosed are novel bicyclic tris(anhydride)s useful as intermediates in the synthesis of biologically active compounds, and the compounds which may be synthesized from such intermediates.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: March 30, 2004
    Assignee: Pharmasset, Ltd.
    Inventors: Krzysztof W. Pankiewicz, Krystyna Lesiak, Kyoichi A. Watanabe
  • Tetraphosphonate bicyclic trisanhydrides
    Patent number: 6326490
    Abstract: Disclosed are novel bicyclic tris(anhydride)s useful as intermediates in the synthesis of biolologically active compounds, and the compounds which may be synthesized from such intermediates.
    Type: Grant
    Filed: October 10, 1997
    Date of Patent: December 4, 2001
    Assignee: Pharmasset, Ltd.
    Inventors: Krzysztof W. Pankiewicz, Krystyna Lesiak, Kyoichi A. Watanabe