Patents by Inventor David L. Hughes

David L. Hughes 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).

  • 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
  • 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
  • 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
  • Patent number: 5126456
    Abstract: An improved process is described which utilizes tetrachloro-1,4(or 1,2)-quinone as an oxidant in the Doebner-Miller synthesis of 7-chloroquinaldine, a starting material in the preparation of leukotriene antagonists. The process improves yield and eliminates the need of forming a ZnCl.sub.2 complex to isolate the end product.
    Type: Grant
    Filed: October 17, 1991
    Date of Patent: June 30, 1992
    Assignee: Merck & Co., Inc.
    Inventors: Zhiguo Song, David L. Hughes
  • Patent number: 5070022
    Abstract: Disclosed is a process for preparing the R and S enantiomers of a compound of the formula; ##STR1## which comprises; (1) reacting an enzyme with a prochiral diester of the formula ##STR2## where M.sup.1 and M.sup.2 are the same, to produce a chiral monoester of the compound of formula II;(2) treating the chiral monoester product of step (1) with an amine and a trialkyl aluminum compound to produce the R enantiomer of the compound of formula I; or reacting the chiral monoester product of step (1) with an acid activating agent, an amine, and a base to produce the S enantiomer of the compound of formula I.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: December 3, 1991
    Assignee: Merck & Co., Inc.
    Inventors: David L. Hughes, Paul J. Reider, Joseph S. Amato, James J. Bergan, Edward J. J. Grabowski
  • Patent number: 4894450
    Abstract: This invention relates to a process for preparing 2-(aminoalkylthio)carbapenems. In particular, this invention relates to a process in which a bis(substituted phenyl) phosphorohalidate is used to form an enol phosphate intermediate that can be converted to 2-(aminoalkylthio)carbapenems by reaction with suitable thioalkylamines.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: January 16, 1990
    Assignee: Merck & Co., Inc.
    Inventors: Edward J. J. Grabowski, David L. Hughes
  • Patent number: 4654433
    Abstract: A simple single step process for preparing alkyl and substituted alkyl esters of amino acids is described. The products are bioactive compounds including compounds useful as antihypertensive agents.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: March 31, 1987
    Assignee: Merck & Co., Inc.
    Inventor: David L. Hughes