Process for the production of a cephamycin derivative

摘要

A chemotherapeutic, antibacterial agent, 7 beta -[(2D-2-amino-2-carboxy)ethylthioacetamido]-7 alpha -methoxy-3-[(1-methyl-1H-tetrazole-5-yl)thiomethyl]-3-cephem-4-carboxylic acid is produced economically and efficiently starting from cephamycin A and/or B by a "new route" process comprising the consecutive steps of reaction of cephamycin with 5-mercapto-1-methyl-1H-tetrazole; protection of the terminal amino group thereof by acylation; protection of the two carboxyl groups thereof by esterification; replacement of the acyl group initially having attached to the 7-amino group by a halogenoacetyl group; deprotection of the blocked 4-carboxyl group; and condensation of D-cysteine with the halogenoacetyl group attaching to the 7-amino group.