PROCESS FOR THE PREPARATION OF 3-HALOGENOCEPHEM DERIVATIVES

摘要

A process for preparing a 3-halogenated cephem derivative represented by the formula (2), characterized by causing a halogenating reagent to act on an allenyl beta -lactam compound represented by the formula (1) in the presence of a cuprous salt or cupric salt to obtain the 3-halogenated cephem derivative wherein R<1> is a hydrogen atom, amino or protected amino, R<2> is a hydrogen atom, halogen atom, lower alkoxyl, lower acyl, lower alkyl, lower alkyl having at least one selected from hydroxyl and protected hydroxyl as a substituent, hydroxyl or protected hydroxyl, R<3> is a hydrogen atom or carboxylic acid protecting group, R<4> is an aromatic compound residue which may have a substituent or nitrogen-containing aromatic heterocyclic compound residue which may have a substituent, and n is 0 to 2 wherein R<1>, R<2> and R<3> are as defined above, X is a halogen atom.