Aminothiazolylacetic acid derivatives and method for preparing the same.

摘要

Aminothiazolylacetic acid derivatives of formula (I) are new. wherein R<1> is an easily cleavable amino-protective group, R<4> and R<5> are different from each other and each is a hydrogen or methyl group, R<6> is a carboxylic acid-protective group, and A is hydrogen, an alkali metal or a quaternary ammonium salt. The compounds are useful as the substituent on the 7-position of antibacterial cephalosporin derivatives. The compounds are obtained by reacting a new compound of formula (II) and a palladium salt or palladium compound in the presence of a triphenylphosphine or trialkyl phosphite and an alkali metal alkanoate or organic base.