ANALOGIFREMGANGSMAATE FOR FREMSTILLING AV TERAPEUTISK AKTIVE CEFEMFORBINDELSER MED TO SUBSTITUERTE 5-LEDDEDE RINGER

摘要

A compound of the formula : wherein R<1> and R<4> are each amino or a protected amino group, R<2> is carboxy(lower)alkyl or a protected carboxy(lower)alky], R<3> is lower alkyl, hydroxy(lower)alkyl or a protected hydroxy(lower)alkyl, and R<5> 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 and their preparation.