Patents by Inventor Dalian Zhao

Dalian 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).

  • Process for N-Boc-N-(R)-2(3-pyridyl)-2-hydroxy-ethyl)-N-2(4-aminophenyl)ethyl amine and 2-(4-aminophenyl)-N-2-(2(R)-hydroxy-2-phyridin-S-yl-ethyl)acetamide
    Patent number: 5792871
    Abstract: Compound 9 is prepared by a 9-step ##STR1## process in an overall yield of about 35% from 3-acetylpyridine. Compound 10 is prepared by a seven-step ##STR2## process in an overall yield of about 30% from 3-acetyl pyridine. These compounds are key intermediates in the synthesis of Compound 11, an important .beta.-3 agonist useful in the treatment of obesity and diabetes.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: August 11, 1998
    Assignee: Merck & Co., Inc.
    Inventors: Michel M. Chartrain, Christopher Roberge, John Y. L. Chung, Dalian Zhao
  • Pyridyl ethylation of lactam derivatives
    Patent number: 5686607
    Abstract: The invention is a highly efficient synthesis for making compounds of formula (iv) wherein R is C.sub.1-4 alkyl or benzyl; and R.sup.1, when present, is C.sub.1-4 alkyl, OH, O--C.sub.1-4 alkyl, or S--C.sub.1-4 alkyl; which are useful intermediates for making compounds such as those represented in formula (I).
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: November 11, 1997
    Assignee: Merck & Co., Inc.
    Inventors: John Y. L. Chung, Dalian Zhao, David J. Mathre
  • Pyridyl ethylation of lactams
    Patent number: 5665882
    Abstract: The invention is a highly efficient synthesis for making compounds of formula: ##STR1## wherein n=0, 1, R is C.sub.1-4 alkyl or benzyl; andR.sup.1, when present, is C.sub.1-4 alkyl, OH, O--C.sub.1-4 alkyl or S--C.sub.1-4 alkyl. The process involves silane-mediated conjugation of 4-vinylpyridine to a substituted lactam.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: September 9, 1997
    Assignee: Merck & Co., Inc.
    Inventors: John Y. L. Chung, Dalian Zhao, James M. McNamara, David L. Hughes
  • Process for preparing fibrinogen receptor antagonists
    Patent number: 5312923
    Abstract: The invention is a highly efficient synthesis for making compounds of the formula: ##STR1## wherein: R.sup.1 is a six membered saturated or unsaturated heterocyclic ring containing one or two heteroatoms wherein the heteroatoms are N; or NR.sup.6, wherein R.sup.6 is H or C.sub.1-10 alkyl;m is an integer from two to six; andR.sup.4 is aryl, C.sub.1-10 alkyl, or C.sub.4-10 aralkyl.
    Type: Grant
    Filed: February 16, 1993
    Date of Patent: May 17, 1994
    Assignee: Merck & Co., Inc.
    Inventors: John Y. L. Chung, David L. Hughes, Dalian Zhao
  • Hydrazine synthesis
    Patent number: 5274096
    Abstract: An improved synthesis is described for producing a quinolinylmethoxyphenyl hydrazine which is an intermediate in the preparation of quinolinylmethoxyindoles useful as inhibitors of leukotriene biosynthesis. The improved process eliminates two isolation steps and yields a product of high purity.
    Type: Grant
    Filed: March 17, 1992
    Date of Patent: December 28, 1993
    Assignee: Merck & Co., Inc.
    Inventors: Joseph F. Payack, Dalian Zhao
  • Process for preparing fibrinogen receptor antagonists
    Patent number: 5206373
    Abstract: The invention is a highly efficient synthesis for making compounds of the formula: ##STR1## wherein: R.sup.1 is a six member saturated or unsaturated heterocyclic ring containing one or two heterocyclic atoms wherein the heteroatoms are N; or NR.sup.6, wherein R.sup.6 is H or C.sub.1-10 alkyl;m is an integer from two to six; andR.sup.4 is aryl, C.sub.1-10 alkyl, or C.sub.4-10 aralkyl.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: April 27, 1993
    Assignee: Merck & Co., Inc.
    Inventors: John Y. L. Chung, David L. Hughes, Dalian Zhao
  • Process for the preparation of 3-unsubstituted indoles using methane sulfonic acid as an additional catalyst
    Patent number: 5157122
    Abstract: An indole having the formula I: ##STR1## is prepared by a Fischer-Indole reaction employing a mixture of phosphorous pentoxide and methane sulfonic acid as an acid catalyst. The reaction, which is optionally run in a co-solvent, provides 3-unsubstituted indoles in high yields with high regioselectivity. The indole thus prepared is an intermediate in the synthesis of leukotriene biosynthesis inhibitors.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: October 20, 1992
    Assignee: Merck & Co., Inc.
    Inventors: David L. Hughes, Dalian Zhao