Thiadiazole derivatives

摘要

3,7-disubstituted-3-cephem-4-carboxylic acid compounds having bacteriostatic properties and the following formula: <IMAGE> in which R1 is thiadiazolyl or isothiazolyl, each of which may have suitable substituent(s), or thiazolyl; R2 is hydrogen or lower alkyl; R3 is carboxy or protected carboxy; R4 is hydrogen, acyloxy or a heterocyclicthio group which may have suitable substituent(s); and R5 is hydrogen or lower alkoxy, process for making same and treating infectious diseases therewith.