The present invention relates to cephalosporins of general formula: ##STR1## in which: R.sub.1 is H or CH.sub.3, R.sub.2 is CH.sub.3, or R.sub.1 and R.sub.2 taken together form a 1,3-propylene group, R.sub.3 is lower alkyl, alkenyl, alkynyl or CH.sub.2 COO alkyl, R.sub.4 is H or OH, the S being bonded to the pyridine ring in 2 or 4 position, A is H or cation or ester or hemiacetal which is easily hydrolyzable, and X is a derivative of a mineral or organic acid. The invention also relates to a process for preparing these new cephalosporins and to the drugs containing said cephalosporins.
本发明涉及一般式为:##STR1## 的
头孢菌素,其中:R.sub.1是H或CH.sub.3,R.sub.2是CH.sub.3,或R.sub.1和R.sub.2一起形成1,3-
丙二烯基,R.sub.3是较低的烷基,烯基,炔基或CH.sub.2COO烷基,R.sub.4是H或OH,S与
吡啶环中的2或4位置结合,A是H或可
水解的阳离子或酯或
半缩醛,X是矿物酸或有机酸的衍
生物。本发明还涉及制备这些新
头孢菌素的方法以及包含这些
头孢菌素的药物。