申请人:Shionogi & Co., Ltd.
公开号:US04647658A1
公开(公告)日:1987-03-03
A useful synthetic intermediate, 7-amino-3-acyloxycepham-4-carboxylic acid aralkyl ester, is prepared by reducing 7-amido-3-oxocepham-4-carboxylic acid aralkyl ester with alkali metal borohydride in a dry organic solvent at temperature lower than -20.degree. C. and then acylating the resulting 3-hydroxycepham compound with an acylating reagent to give 3-acyloxycepham compound, and then subjecting the 3-acyloxycepham compound to amide cleavage consisting of treatments (1) with a mixture of phosphorus pentachloride and aromatic base giving imino-chloride and (2) with alcohol for converting the latter into imino-ether and for subjecting the product to alcoholysis giving the objective compound.
一个有用的合成中间体,7-氨基-3-酰氧头孢烯-4-羧酸芳基酯,是通过在低于-20摄氏度的干燥有机溶剂中用碱金属硼氢化物还原7-氨基-3-氧代头孢烯-4-羧酸芳基酯制备的,然后用酰化试剂酰化得到3-羟基头孢烯化合物,然后将3-酰氧头孢烯化合物经过酰胺裂解,包括处理(1)与磷五氯化物和芳香碱的混合物生成亚胺氯化物和(2)与醇反应将后者转化为亚胺醚,并将产物经醇解得到目标化合物。