Methods for the manufacture of cephems

摘要

Provided is a process for preparing a cephem compound of the formula: <IMAGE> wherein R3 is hydrogen or methoxy, R4 is hydrogen or a residue of a nucleophilic compound, R5 is hydroxyl or a protected hydroxyl, and R8 is hydrogen or halogen, or a pharmaceutically acceptable salt or ester thereof, which comprises introducing an acyl group of the formula: <IMAGE> wherein R5 and R8 are as defined above into the amino group of the molecule of the formula: <IMAGE> wherein R3 and R4 are as defined above or a salt or ester thereof.