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:
Mar. 12, 1996
Filed:
Apr. 20, 1994
Applicant:
Inventors:
Hui-Po Wang, Taipei, TW;
Jia-Shuai Lee, Taipei, TW;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
540222 ; 540226 ; 540227 ; 540225 ; 540228 ;
Abstract
A method for preparing cephalosporm derivatives by reacting cephalosporin alkaline metal salts with organic halide in the presence of quaternary ammonium salts catalyst is disclosed. .DELTA..sup.3 .fwdarw..DELTA..sup.2 isomerization, a side reaction commonly reported in preparation of cephalosporin derivatives was successfully eliminated. The desired .DELTA..sup.3 was obtained as a sole product in the reaction.