A process for the preparation of cephalosporin antibiotic of the formula (I) wherein R1 represents hydrogen, trityl, etc,; R3 is carboxylate ion or COORd, where Rd represents hydrogen, ester or a counter ion which forms a salt; R4 represents H, OCH3, OCOCH3, =CH2, OCONH2, etc, which comprises: (i) condensing the activated derivative of the formula (III) where X represents halogen atom, with 7-amino cephalosporin derivative of the formula (XV) wherein R represents hydrogen, lower alkyl, etc, in the presence of a solvent at a temperature in the range of -50 °C to +50 °C to produce a compound of formula (XVI) ii) maintaining the pH in the range 5.0-10.0 using an inorganic base, iii) cyclizing the compound of formula (XVI) with thiourea to produce compound of formula (I).
一种制备
头孢菌素抗生素的方法,其中公式(I)中R1代表氢、三苯甲基等;R3是
羧酸盐离子或COORd,其中Rd代表氢、酯或形成盐的反离子;R4代表H、OCH3、OCOCH3、=
CH2、OCONH2等,包括以下步骤:(i)在溶剂存在下,在温度范围为-50℃至+50℃的条件下,将公式(III)的活性衍
生物(其中X代表卤素原子)与公式(XV)的7-
氨基
头孢菌素衍
生物(其中R代表氢、较低的烷基等)缩合,以产生公式(XVI)的化合物;(ii)使用
无机碱维持pH在5.0-10.0范围内;(iii)使用
硫脲将公式(XVI)的化合物环化,以产生公式(I)的化合物。