A 7-acylamido-3-substituted thio-3-cephem-4-carboxylic ester of general formula (5) can be produced preferentially, readily and efficiently by reacting 7-acylamido-3-acylthio-3- or 2-cephem-4-carboxylic ester of general formula (1) (wherein R¹ represents acyl, R² represents a protective group of the carboxyl group, and R³ represents lower alkyl or (un)substituted aryl) or a mixture thereof with tertiary and secondary amines and further reacting a tertiary amine salt of the reaction product with a compound of general formula (4): R⁴-X, wherein R⁴ represents lower alkyl, cycloalkyl, heterocycle or heterocycle-substituted methyl and X represents a leaving group.
通式(5)的7-乙酰
氨基-3-取代
硫-3-头孢-4-
羧酸酯可通过使通式(1)的7-乙酰
氨基-3-乙酰
硫-3-或2-头孢-4-
羧酸酯(其中R¹代表酰基、R²代表羧基的保护基团,R³代表低级烷基或(未)取代的芳基)或其混合物与叔胺和仲胺反应,再将反应产物的叔胺盐与通式(4)化合物反应:其中 R⁴ 代表低级烷基、环烷基、杂环或杂环取代的甲基,X 代表离去基团。