NEW CEPHEM COMPOUNDS AND PROCESSES FOR PREPARATION THEREOF

摘要

A compound of the formula : wherein R<1> is amino or a protected amino group, Z is N or CH, R<2> is an organic group, and R is a group of the formula : (in which R<3> and R<4> are each lower alkyl, or R<3> and R<4> are linked together to form C3-C6 alkylene, A is lower alkylene, and R<5> is hydroxy or a protected hydroxy group) or a group of the formula : (in which R<6> is lower alkyl, R<7> and R<8> are each hydroxy or a protected hydroxy group, and Y is N or CH), and a pharmaceutically acceptable salt thereof, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient. The invention relates also to intermediates of the formula and their preparation. o