Processes for the preparation of lower alkyl - 2 or 3 -cephem-4-carboxylic acid derivatives, new products thus obtained and their use as products with antimicrobial activity.

摘要

A compound of the formula IMAGE wherein R1 is amino or substituted amino, R2 is carboxy or protected carboxy, R3 is lower alkyl and X is -S- or IMAGE or a pharmaceutically acceptable salt thereof is effective against various microorganisms.