Patents by Inventor Huynh-Ba Tuong

Huynh-Ba Tuong 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).

  • Production of quinic acid derivatives
    Patent number: 5395950
    Abstract: 1-, 5-O-mono- and 3,4-0-bis-substituted derivatives of quinic acid are prepared by reacting a derivative of a hydroxycinnamic acid of which the hydroxyl group(s) is/are protected with a quinic acid derivative to form an ester and the protective groups are then cleaved under controlled conditions of acidity and temperature. These conditions provide for regiospecificity of the esterification and enable any degradation of isomerization to be avoided. The process gives new quinides in high yields.
    Type: Grant
    Filed: July 21, 1993
    Date of Patent: March 7, 1995
    Assignee: Nestec S.A.
    Inventor: Huynh-Ba Tuong
  • Anisotropic compounds and liquid crystal mixtures
    Patent number: 4514317
    Abstract: Anisotropic compounds having negative DC anisotropy and improved photochemical stability have the formula (1) given in patent claim 1; none of the benzene rings present in the molecule (1) is bonded directly to two oxygen atoms, as a result of which quinoidal bonding states which reduce the photochemical stability of anisotropic compounds in the case of benzene rings with two lateral nitrile groups are excluded.
    Type: Grant
    Filed: January 25, 1983
    Date of Patent: April 30, 1985
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Huynh-Ba Tuong, Stephen M. Kelly, Maged A. Osman