Patents by Inventor Mangzu Zhao

Mangzu Zhao 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).

  • Oxidation process using periodic acid
    Patent number: 6172231
    Abstract: The present invention relates to a periodic acid oxidation which converts the penultimate intermediate bearing a primary alcohol to the target endothelin antagonist compound of Formula I having a carboxylic acid.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: January 9, 2001
    Assignee: Merck & Co., Inc.
    Inventors: Zhiguo Song, Mangzu Zhao, David M. Tschaen
  • Oxidation process using periodic acid
    Patent number: 6150554
    Abstract: The present invention relates to an oxidation which converts a primary or secondary alcohol of Formula II: ##STR1## to an acid or ketone of Formula I: ##STR2## with periodic acid and a catalytic amount of a chromium reagent.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: November 21, 2000
    Assignee: Merck & Co., Inc.
    Inventors: Jing Li, David M. Tschaen, Zhiguo Song, Mangzu Zhao
  • Oxidaton of primary alcohols to carboxylic acids with a TEMPO catalyst using NaClO.sub.2 and NaClO
    Patent number: 6127573
    Abstract: The present invention relates to a TEMPO-catalyzed oxidation of primary alcohols, RCH.sub.2 OH to corresponding carboxylic acids, RCOOH in the presence of catalytic in the presence of catalytic amount of NaClO and stoichiometric amount of NaClO.sub.2 as an oxidant.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: October 3, 2000
    Assignee: Merck & Co., Inc.
    Inventors: Jing Li, Zhiguo Song, David M. Tschaen, Mangzu Zhao
  • Phosphate-mediated cyclization
    Patent number: 6046327
    Abstract: This invention relates to a cyclization process useful in the preparation of a key intermediate in the preparation of an endothelin antagonist of the general formula shown below: ##STR1##
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: April 4, 2000
    Assignee: Merck & Co., Inc.
    Inventors: Richard D. Tillyer, David M. Tschaen, Zhiguo Song, Mangzu Zhao
  • Oxidation process using tempo
    Patent number: 6031101
    Abstract: The present invention relates to an oxidation using sodium chlorite in the presence of a catalytic amount of TEMPO and sodium hypochlorite which converts the penultimate intermediate bearing a primary alcohol to the target endothelin antagonist compound of Formula I having a carboxylic acid ##STR1##
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: February 29, 2000
    Assignees: Merck & Co., Inc., Banyu Pharmaceuticals Co., Ltd
    Inventors: Paul N. Devine, Eiichi Mano, Zhiguo Song, David M. Tschaen, Mangzu Zhao