Process for preparing cephalosporins

摘要

An improved process for preparing antibacterially active 7- alpha -aminoacetamido cephalosporin-4-carboxylic acids in which a 7-aminocephalosporin-4-carboxylic acid ester is reacted with an activated form of an alpha -aminoacetic acid, the amino group of which is protected by a beta -dicarbonyl group, this amino group being removed after the acylation in the presence of a sufficient amount of a hydrazine derivative to prevent re-reaction of the beta -dicarbonyl protecting agent with the cephalosporin.