A process for producing a 2-cephem or 3-cephem derivative compound of the formula: ##STR1## wherein R.sub.1 represents a substituted or unsubstituted amino radical and R.sub.4 represents hydrogen or a radical selected from the group consisting of carboxy, protected carboxy, ester, acid amide, acid anhydride, acid halide, acid azide and carboxy salt, and the dotted line indicates the alternate bond structure providing 3-cephem or 2-cephem, which comprises: reacting a halogenated derivative selected from the group consisting of a halogenated penam derivative having the formula: ##STR2## a halogenated cephem derivative of the formula: ##STR3## wherein X represents a halogen atom, R.sub.3 represents a radical selected from the group consisting of carboxy, protected carboxy, ester, acid amide, acid anhydride, acid halide, acid azide and carboxy salt, and R.sub.1 is as defined above, or mixtures thereof with a dehydrohalogenoic acid reagent.
一种生产2-
头孢菌素或3-
头孢菌素衍
生物的方法,该衍
生物的
化学式为:## STR1 ## 其中R.sub.1代表取代或未取代的
氨基基团,R.sub.4代表氢或从羧基,保护羧基,酯,酸酰胺,酸酐,酸卤,酸
叠氮和
羧酸盐选择的基团,虚线表示提供3-
头孢菌素或2-
头孢菌素的交替键结构,所述方法包括:将选择自羧基,保护羧基,酯,酸酰胺,酸酐,酸卤,酸
叠氮和
羧酸盐的基团,且R.sub.1如上定义的卤代的青霉烷衍
生物的反应物,选择自以下羧基,保护羧基,酯,酸酰胺,酸酐,酸卤,酸
叠氮和
羧酸盐的基团,且R.sub.1如上定义的卤代的
头孢菌素衍
生物的反应物,或两者的混合物与脱卤酸试剂反应。