4-甲基噻唑-5-甲酸乙酯的一步法合成工艺研究

Study on the One Step Synthesis of Ethyl 4-methylthiazole-5-carboxylate

研究了头孢托仑酯关键中间体4-甲基噻唑-5-甲酸乙酯1的一步法合成新工艺,以2-氯乙酰乙酸乙酯(2)为起始原料,与硫氰酸铵无溶剂条件下缩合反应制得。收率达到92%。该过程条件温和,操作简便,后处理简单,避免了传统工艺收率低,废液量大,操作复杂等缺陷。具有工业化应用前景。

Ethyl 4-methylthiazole-5-carboxylate1,a key intermediate of Cefditoren pivoxil,was synthesizd from Ethyl 2-chloroacetoacetate and Ammonium thiocyanate via condensation reaction. The yield is over 92% and the advantages of the present procedure are mild reaction operation,easy operation and simple work up,it avoids such defects as low yield,large sale liquid wastes and complex operation of traditional procedure. So it can be expected to have a good prospect for industrial application.