| 摘要 |
<p>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.</p> |
