7-氨基-3-无-3-头孢环-4-羧酸的制备

The Preparation of 7-Amino-3-Nor-3-Cephalocyph-4-Carboxylic Acid

以7-苯乙酰氨基-3-羟基头孢-4-羧酸二苯甲酯(3-HCA)为起始原料,在乙基磺酰氯和三乙胺的作用下酯化、消去得7-苯乙酰氨基-3-无-3-头孢-4-羧酸二苯甲酯(化合物2);化合物2在氯化气和苯甲醚作用下,脱去羧基保护基,得7-苯乙酰氨基-3-无-3-头孢-4-羧酸(化合物3);化合物3经酶解脱去苯乙酰基,从而得到7-ANCA。改进后的合成路线不使用剧毒品,操作简单,收率高,对环境污染小,是一种适合工业化生产的合成方法。

Using 7-phenylacetamino-3-hydroxycephalosporin-4-carboxylate dimethyl ester(3-HCA)as starting material,7-phenylacetamino-3-nor-3-cephalosporin-4-carboxylate dimethyl ester(compound 2)was obtained by esterification and elimination under the reaction of ethyl sulfonyl chloride and triethylamine.Under the reaction of chloride gas and anisole,the carboxyl protective group was removed from compound 2,then obtain 7-phenylacetamino-3-nor-3-cephalosporin-4-carboxylic acid(compound 3).Remove phenylacetyl by enzymolysis for Compound 3 to obtain 7-ANCA.The improved synthesis route does not use highly toxic products,simple to operate,high yield and little environmental pollution,and is a suitable synthesis method for industrial production.