A process for the manufacture of a cephalosporin derivative of the formula I ##STR1## in which X is sulphur, oxygen or sulphinyl; R.sup.1 is any one of the C-3 substituents from antibacterially-active cephalosporins known in the art; R.sup.2 is hydrogen or 1-6C alkyl; R.sup.3 is hydrogen or 1-6C alkyl; and the pharmaceutically-acceptable acid-addition and base-addition salts thereof, characterized by cyclization of a compound of the formula II: ##STR2## or a derivative thereof in which the carbonyl group is masked, or an acid-addition salt thereof, in which R.sup.4 and R.sup.5 individually have one of the values for R.sup.2 and R.sup.3, R.sup.6 is a nitrogen-protecting group and R.sup.7 is hydrogen or any one of the cephalosporin 3-carboxylic acid protecting groups known in the art; whereafter when the product from the cyclization retains the protecting group R.sup.7 (when R.sup.7 is other than hydrogen) the protecting group R.sup.7 is replaced by hydrogen by conventional means; and whereafter when the compound of the formula I is obtained in the form of the free base or salt, and a pharmaceutically-acceptable salt or free base respectively is required, any necessary conversion between free base and salt is carried out by conventional means.
一种制备公开的
头孢菌素衍
生物的方法,其
化学式为I,其中X为
硫、氧或亚砜;R.sup.1为在已知具有抗菌活性的
头孢菌素中的任一C-3取代基;R.sup.2为氢或1-6C烷基;R.sup.3为氢或1-6C烷基;以及其药学上可接受的酸加合物和碱加合物盐,其特征在于将化合物的环化II的环化化合物:##STR2## 或其衍
生物(其中羰基团被掩蔽),或其酸加合物盐,其中R.sup.4和R.sup.5分别具有R.sup.2和R.sup.3的值之一,R.sup.6是氮保护基,R.sup.7是氢或在已知的
头孢菌素3-羧基保护基中的任一种;随后当环化产物保留保护基R.sup.7(当R.sup.7不是氢时),通过常规手段将保护基R.sup.7替换为氢;随后当以游离碱或盐的形式获得化合物I时,如果需要药学上可接受的盐或游离碱,则通过常规手段进行自由碱和盐之间的必要转化。