A cephalosporin derivative of the formula I: ##STR1## in which X is S, O, CH.sub.2 or SO, R1 is (optionally-substituted) imidazol-2-yl or one of the C-7 acyl groups known in the cephalosporin art, R2 is hydrogen or methoxy, R3 is carboxy or a biodegradable ester thereof and -R4 is of the formula XII, XIII or XIV: ##STR2## in which R32-R40 inclusive are as defined in the specification; and the salts thereof. Pharmaceutical compositions, methods of manufacture and intermediates are also described.
一种
头孢菌素衍
生物,
化学式为I:##STR1## 其中X为S,O,CH.sub.2或SO,R1为(可选取代的)
咪唑-2-基或
头孢菌素艺术中已知的C-7酰基之一,R2为氢或甲氧基,R3为羧基或其
生物可降解的酯,-R4为
化学式XII,XIII或XIV:##STR2## 在其中
R32-R40包括如规范中定义的;以及其盐。还描述了制药组合物、制造方法和中间体。