The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 1992
Filed:
May. 06, 1991
Applicant:
Inventors:
Assignee:
Ranbaxy Laboratories Limited, New Delhi, IN;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
540215 ; 540230 ;
Abstract
A one-pot process for preparing 7-amino-3-exomethylene-3-cepham-4-carboxylic acid ester (II) comprises: (a) reacting 7-acylamino-3-exomethylene-3-cepham-1-oxide-4-carboxylic acid ester (I) with a silylating agent in an inert solvent and in the presence of a base, (b) adding a phosphorous halide to produce an iminohalide, and (c) adding an anhydrous alcohol. In a preferred embodiment, the silylating agent comprises trimethylchlorosilane, and the phosphorous halide comprises phosphorous pentachloride.