NEW CEPHEM COMPOUNDS

摘要

New cephem compounds of formula (I), wherein R1 is amino or protected amino, R2 is hydrogen, lower alkyl or hydroxy protective group, R3 is carboxy or protected carboxy, R4 is 3-pyridyl, 4-pyridyl or optionally substitued heteromonocyclic group containing two nitrogen atoms as hetero atoms, and which may also contain one oxygen or sulfur atom, and n is 0, 1 or 2, provided that when R2 is lower alkyl, then n is 1 or 2 and R4 is optionally substituted heteromonocyclic group containing two nitrogen atoms as hetero atoms, and which may also contain one oxygen or sulfur atom, and pharmaceutically acceptable salts thereof which are useful as a medicament.