PROCESS FOR THE PREPARATION OF CEPHALOSPORIN ANTIBIOTICS.

摘要

The present invention more particularly relates to a process for the preparation of cephalosporin antibiotics of the formula (I) wherein R1 represents hydrogen, trityl, CH3, CRaRbCOORc where Ra and Rb independently represent hydrogen or methyl and Rc represents hydrogen or (C1- C6)alkyl; R2 is carboxylate ion or COORd, where Rd represents hydrogen, ester or a counter ion which forms a sa R3 represents hydrogen, CH3, CH2ococh, CH=CH2,