Patents by Inventor Janak Singh

Janak Singh 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: 5233086
    Abstract: Racemic Feist's acid is treated with (R)-(+)-.alpha.-methylbenzylamine to yield (1R-trans)-3-methylene-cyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: August 3, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Jollie D. Godfrey, Jr., Richard H. Mueller, Thomas P. Kissick, Janak Singh
  • Patent number: 5218142
    Abstract: Racemic Feist's acid is treated with (R)-(+)-.alpha.-methylbenzylamine to yield (1R-trans)-3-methylenecyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta.,3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobut yl]-1,9-dihydro-6H-purin-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: June 8, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Jollie D. Godfrey, Jr., Richard H. Mueller, Thomas P. Kissick, Janak Singh
  • Patent number: 5210262
    Abstract: A method is provided for preparing a phosphonic acid ester having the structure ##STR1## wherein R.sup.1 is farnesyl or a derivative or analog thereof, and R.sup.2 is lower alkyl, by treating a farnesyl halide R.sup.1 Hal(Hal=Cl,Br,I) with an alkoxide of the structure ##STR2## wherein M is an alkali metal and R.sup.2c is lower alkyl. The resulting phosphonic acid ester is an intermediate in preparing a squalene synthetase inhibitor which is used for inhibiting cholesterol biosynthesis.
    Type: Grant
    Filed: September 14, 1992
    Date of Patent: May 11, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Janak Singh, Richard H. Mueller
  • Patent number: 5194604
    Abstract: Disclosed herein are processes for preparing a compound of the formula ##STR1## in which a novel compound of the formula ##STR2## is reacted with a beta lactam of the formula ##STR3## by treatment with a base, wherein the symbols are as defined in the specification.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: March 16, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Theodor Denzel, Christopher M. Cimarusti, Janak Singh, Richard H. Mueller
  • Patent number: 5185463
    Abstract: Racemic Feist's acid is treated with (R)-(+)-.alpha.-methylbenzylamine to yield (1R-trans)-3-methylenecyclopropane-1,2-dicarboxylic acid, (R)-.alpha.-methylbenzylamine (1:1) salt. This salt can then be converted to (1R-trans)-3-methylene-1,2-cyclopropanedicarboxylic acid, dimethyl ester which is an intermediate in the preparation of the antiviral agent [1R-(1.alpha.,2.beta., 3.alpha.)]-2-amino-9-[2,3-bis(hydroxymethyl)cyclobutyl]-1,9-dihydro-6H-pur in-6-one. The improved process also enables the recovery of racemic Feist's acid from the resolution.
    Type: Grant
    Filed: October 2, 1991
    Date of Patent: February 9, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Jollie D. Godfrey, Jr., Richard H. Mueller, Thomas P. Kissick, Janak Singh
  • Patent number: 5177239
    Abstract: A method is provided for preparing a phosphonic acid ester having the structure ##STR1## wherein R.sup.1 is farnesyl or a derivative or analog thereof, and R.sup.2 is lower alkyl, by treating a farnesyl halide R.sup.1 Hal(Hal.dbd.Cl,Br,I) with an alkoxide of the structure ##STR2## wherein M is an alkali metal and R.sup.2c is lower alkyl. The resulting phosphonic acid ester is an intermediate in preparing a squalene synthetase inhibitor which is used for inhibiting cholesterol biosynthesis.
    Type: Grant
    Filed: July 17, 1989
    Date of Patent: January 5, 1993
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Janak Singh, Richard H. Mueller
  • Patent number: 4973747
    Abstract: A process has now been discovered by which an intermediate in preparation of antibiotics ##STR1## may be directly derived from the substrate ##STR2## by treatment with aqueous solutions of MHCO.sub.3 and MOH, wherein: R.sup.1, R.sup.2 and R.sup.3 are each independently alkyl, alkenyl, alkynyl, substituted alkyl, substituted alkenyl, substituted alkynyl, aryl, or substituted aryl;M is alkali metal (such as Na, Li, or K); andX is halogen.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: November 27, 1990
    Assignee: E. R. Squibb & Sons, Inc.
    Inventors: Janak Singh, Richard H. Mueller