Patents by Inventor Ravindra S. Topgi

Ravindra S. Topgi 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).

  • Method and apparatus for preparation of chiral beta amino acids using penicilln G acylase
    Patent number: 6214609
    Abstract: A method for preparing a chiral beta amino acid or its corresponding esters which comprises contacting a racemic beta amino acid, an acyl donor and Penicillin G acylase enzyme under conditions appropriate to stereoselectively acylate one enantiomer of the racemic beta amino acid to its corresponding N-acylated derivative whereby the opposite enantiomer of the beta amino acid is retained in enantiomerically enriched form.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: April 10, 2001
    Assignee: Monsanto Company
    Inventors: Bryan H. Landis, John S. Ng, Ravindra S. Topgi, Edward E. Yonan, Ping T. Wang
  • Asymmetric synthesis of chiral beta-amiNo acids
    Patent number: 5840961
    Abstract: The invention herein is directed to a process for the preparation of ethyl 3S-amino-4-pentynoate which involves treating 3-(trimethylsilyl)-2-propynal with L-phenylglycinol in toluene to produce .alpha.S-??3-(trimethylsilyl)-2-propynylidene amino!benzenethanol; reacting .alpha.S-??3-(trimethylsilyl)-2-propynylidene!amino!benzenethanol with BrZnCH.sub.2 CO.sub.2 t-Bu in THF/NMP to produce 1,1-dimethylethyl 3S-?(2-hydroxy-1S-phenylethyl)amino!-5-(trimethylsilyl)-4-pentynoate; reacting the 1,1-dimethylethyl 3S-?(2-hydroxy-1S-phenylethyl)amino!-5-(trimethylsilyl)-4-pentynoate with sodium periodate to form 1,1-dimethylethyl 3S-?(phenylmethylene)amino!-5-(trimethylsilyl)-4-pentynoate; hydrolyzing 1,1-dimethylethyl 3S-?(phenylmethylene)amino!-5-(trimethylsilyl)-4-pentynoate to produce 1,1-dimethylethyl 3S-amino-5-(trimethylsilyl)-4-pentynoate; transesterifying 1,1-dimethyl 3S-amino-5-(trimethylsilyl)-4-pentynoate and desilylating to produce ethyl 3S-amino-4-pentynoate.
    Type: Grant
    Filed: July 10, 1997
    Date of Patent: November 24, 1998
    Assignee: G. D. Searle & Co.
    Inventors: James Richard Behling, Mark Laurence Boys, Kimberly Jo Cain-Janicki, Pierre-Jean Colson, Wendel William Doubleday, Joseph Edward Duran, Payman N. Farid, Carl Matthew Knable, Frank Walter Muellner, Sean Thomas Nugent, Ravindra S. Topgi