New cephem compounds and processes for preparation thereof.

摘要

New cephem compounds of the formula:
<CHEM>
wherein
R<1> is amino or a protected amino group;
R<2> is hydrogen, lower aliphatic hydrocarbon group which may be substituted with suitable substituent(s), cyclo(lower)alkyl, or cyclo(lower)alkenyl;
R<3> is lower alkyl which mad be substituted with suitable substituents(s);
R<3a> is hydrogen, lower alkyl or amino; and R<3b> is hydrogen or lower alkyl; and
pharmaceutically acceptable salts thereof, and processes for their preparation and a pharmaceutical antibacterial composition comprising them in association with a pharmaceutical antibacterial composition comprising a compound of claim 1 in association with a pharmaceutically acceptable, substantially non-toxic carrier or excipient.