Method for preparing cephalosporin derivatives

摘要

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 3-> DELTA 2 isomerization, a side reaction commonly reported in preparation of cephalosporin derivatives was successfully eliminated. The desired DELTA 3 was obtained as a sole product in the reaction.