Patent ID: 8071330

Claim:
A process for the synthesis of cefaclor, said process comprising reacting 7-amino -3-chloro cephalosporanic acid (7-ACCA) and a mutant penicillin acylase of E. coli having a beta subunit wherein said mutant penicillin acylase has L-alanine substituted for L-phenylalanine at position 24 of the beta-subunit with added D-phenylglycine methyl ester in a reaction mixture at a pH of 7 to form cefaclor, wherein the added D-phenylglycine methyl ester is added at a constant rate for at least 90 minutes to the reaction mixture during the course of the reaction, wherein the added D-phenyl glycine methyl ester is added in a total amount to the reaction mixture in a 1.1 molar ratio to the 7-ACCA .