An Improved Synthesis of (Z)-2-(5-Amino-1,2,4-thiadiazol-3-yl)-2- (ethoxyimino) acetic Acid
作者:Songqing Wang、Yi Yao、Kai Chen、Zhujun Fang、Lexian Tong、Weihui Zhong
DOI:10.2174/1570178611888140602160120
日期:2014.6
An improved synthetic route of (Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(ethoxyimino)acetic acid (2a), an important intermediate for the preparation of Ceftaroline, from N-(3-aminoisoxazol-5-yl)acetamide (8) in total yield of 47% has been developed. The key intermediate (Z)-N-(3-(2-acetamido-1-(ethoxyimino)-2-oxoethyl)-1,2,4-thiadiazol-5- yl)pivalamide (12a) was easily isolated from (Z/E)-N-(3-(2-a
改进的合成方法(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-(乙氧基亚氨基)乙酸(2a)是制备头孢洛林的重要中间体已开发出N-(3-氨基异恶唑-5-基)乙酰胺(8),总产率为47%。从(Z)中容易分离出关键中间体(Z)-N-(3-(2-乙酰氨基-1-(乙氧基亚氨基)-2-氧代乙基)-1,2,4-噻二唑-5-基)新戊酰胺(12a) / E)-N-(3-(2-乙酰氨基-1-(乙氧基亚氨基)-2-氧代乙基)-1,2,4-噻二唑-5-基)新戊酰胺。通过水解12a获得标题化合物2a,产率为83%,并且通过X射线单晶衍射分析确认了其结构。此外,分别由(E)-和(Z)-N-(3-(2-乙酰氨基-1-(乙氧基亚氨基)-2-氧代乙基)-1,2,4-噻二唑-5-基)新戊酰胺制备。肟羟基在不同条件下的醚化。