PROCESS FOR PRODUCING NEW CEFEM DERIVATIVES AND PHARMACEUTICAL COMPOSITIONS COMPRISING SAME

摘要

A compound of the formula : CHEM wherein R1 and R4 are each amino or a protected amino group, R2 is carboxy(lower)alkyl or a protected carboxy(lower)alky], R3 is lower alkyl, hydroxy(lower)alkyl or a protected hydroxy(lower)alkyl, and R5 is hydrogen or lower alkyl, and a pharmaceutically acceptable salt thereof, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient. The invention further relates to intermediate compounds of the formula CHEM and their preparation.