7-Alkoxy-3-bromomethyl-3-cephems are provided by reacting a 3-methylenecepham with an alkali metal salt of a lower primary alcohol in the presence of a positive brominating agent at a temperature ranging from about -80.degree. to about 0.degree. C. The 3-bromomethylcephems provided by this invention are useful intermediates for the preparation of known cephalosporin antibiotics.
本发明提供了通过在较低初级醇的碱
金属盐存在下,在正
溴代试剂的存在下,在温度约为-80°C至约0°C之间反应3-亚甲基
头孢菌素与醇氧基制备7-烷氧基-3-
溴甲基-3-
头孢菌素。本发明提供的3-
溴甲基头孢菌素是制备已知
头孢菌素抗生素的有用中间体。