| 摘要 |
<p>PURPOSE:To produce a stable aminothiazolylacetic acid halide derivative in high purity. CONSTITUTION:A compound of formula I (R<1> is lower alkyl, cycloalkyl or lower alkyl halide; R<2> is amino-protecting group or H) or its salt is made to react with a halogenating reagent, that is, Vilsmeier's reagent prepared by reacting an acid amide or phosphoric acid amide with a halogenating agent or made to react with the other halogenating agent (preferably phosphorus pentachloride) in the presence of water to afford an acid halide of formula II, and then, the reaction liquid is poured into water and a free substance is isolated from the water or hydrogen halide salt thereof is isolated by depositing the salt from the reaction liquid to provide the objective aminothiazolylacetic acid halide derivative or its salt. The higher purity of the objective derivative is further attainable by using the compound of formula I having <=30mum, especially <=10mum particle diameter as the raw material. The compound of formula II is useful as an acylating agent for selecting 7beta-acylaminocephalosporin derivative having excellent antimicrobial activity.</p> |
