3-Pyrrolidinylthio-1-azabicyclo(3,2,0) hept-2-ene-2-carboxylic acid compounds.

摘要

A compound of the formula : in which R<1> is carboxy or protected carboxy, R<2> is hydroxy(lower)alkyl or protected hydroxy(lower)alkyl, R<3> is hydrogen or lower alkyl, R<4> is unsaturated heterocyclic group which may be substituted by suitable substituent(s), R<5> is hydrogen, lower alkanimidoyl or imino-protective group, and A is lower alkylene, or pharmaceutically acceptable salts thereof, processes for their preparation and pharmaceutical compositions comprising them as an active ingredient in admixture with a pharmaceutically acceptable carrier or excipient.