1. A compound of the formula:
in which R1 is thiadiazolyl, R2 is carboxy(lower)alkyl or protected carboxy(lower)alkyl, R3 is hydrogen, halogen or lower alkenyl, and R4 is carboxy or a protected carboxy group, and pharmaceutically acceptable salts thereof, and processes for the preparation of the same and pharmaceutical compositions comprising the same in admixture with pharmaceutically acceptable carriers.
1.式中的化合物:
其中 R1 是
噻二唑基,R2 是羧基(低级)烷基或受保护的羧基(低级)烷基,R3 是氢、卤素或低级烯基,R4 是羧基或受保护的羧基,及其药学上可接受的盐,以及制备上述化合物和由上述化合物与药学上可接受的载体混合而成的药物组合物的工艺。