Sefuamaishinkoseibutsushitsunoseizonokairyoho

摘要

An improved process for preparing the antibiotic compound 7 beta -(2-thienylacetamido)-7-methoxy-3-carbamoyloxymethyl-3-cephem-4-carbox ylic acid, from the N-blocked esters of the compound 7 beta -(D-5-amino-5-carboxyvaleramido)-3-carbamoyloxymethyl-7-methoxy-3-ceph em-4-carboxylic acid (Cephamycin C), by conducting the transacylation of the latter in a homogenous solution containing N-trimethylsilyl loweralkyl carbamates.