Cephem compounds having 3-bicyclic heterocyclic cation groups

摘要

The invention relates to cephem compounds of high antimicrobial activity of the formula: <IMAGE> wherein R1 is amino or protected amino, R2 is lower aliphatic hydrocarbon group, R3 is a group of the formula: <IMAGE> wherein m is 0 and or 1, and n is 1 or 2, which may have a lower alkyl substituent at the N atom, and X is CH or N, and pharmaceutically acceptable salts thereof.