A PROCESS FOR THE PREPARATION OF CEPHALOSPORIN INTERMEDIATE AND ITS USE FOR THE MANUFACTURE OF CEPHALOSPORIN COMPOUNDS

摘要

The present invention relates to a process for the preparation of 4-halogeno-2-substitutedimino-3-oxo-butyric acid of formula (I) wherein R1 represents CH3, CRaRbCOORc where Ra and Rb independently represent hydrogen or methyl and Rc represents hydrogen or (C1-C6)alkyl, X represents halogen such as chlorine or bromine, also discloses the activation of this acid and its further use in the preparation of cephalosporanic antibiotics (II) in excellent yields and purity.