Cephem compounds and processes for preparation thereof.

摘要

New cephem compounds of the formula:
<CHEM>
wherein
R<1> is amino or protected amino,
R<2> is aryl which may have suitable substituent(s), a heterocyclic group which may have suitable substituent(s), cyano, hydrogen or tri(lower)alkylsilyl,
R<3> is carboxy or protected carboxy, and
A is -CH = CH- or -C IDENTICAL C-,
and pharmaceutically acceptable salt thereof, processes for their preparation and pharmaceutical compositions containing them in association with a pharmaceutically acceptable, substantially non-toxic carrier or excipient. The invention also relates to intermediates of the formula
<CHEM>
and processes for their preparation.