Cephem compounds and processes for preparation thereof.

摘要

1. A compound of the formula:
<CHEM>
wherein R<1> is lower alkyl, lower alkanoyl, aryl, ar(lower)alkyl or a heterocyclic group, each of which may have suitable substituent(s),
R<2> is carboxy or protected carboxy,
R<3> is hydrogen, halogen, hydroxy, lower alkoxy, acyloxy, lower alkylthio, lower alkenyl, lower alkenylthio, lower alkynyl, heterocyclicthio or a heterocyclic group, in which lower alkylthio, lower alkenyl, lower alkenylthio, heterocylicthio and a heterocyclic group may have suitable substituent(s),
R<4> and R<5> are each hydrogen, halogen or arylthio,
A is lower alkylene, and
n is an integer of 0 or 1,
and a pharmaceutically acceptable salt thereof,
processes for preparation thereof and pharmaceutical composition comprising the same.