麦草畏及其中间体的合成评述

对麦草畏及其中间体的合成方法进行了简要介绍,并通过比较确定了麦草畏原药工业生产的较优合成路线,即以2,5-二氯苯胺为原料,在高温条件下快速进行部分重氮化,快速高温水解,与水共沸得到2,5-二氯苯酚;后经成盐脱水、以碳酸钾和三乙胺的混合物(摩尔比1∶1.6)为催化剂通CO2羧化、酸化合成3,6-二氯水杨酸,再溶入有机溶剂中,用硫酸二甲酯进行O-烷基化反应,水解、酸化得到成品,其总收率为66.7%。

Synthetic Reviews on Dicamba and Its Intermediates

A recent review on the synthesis of dicamba and its key intermediates was introduced.Through analysis and comparison of different routes referred,a better route was identified to synthesize dicamba technical with its theoretical yield of 66.7%: starting from diazotization-hydrolyzation of 2,5-dichloroaniline with nitrite in sulfuric acid,and then salifying,feeding CO2 to initiate Kolbe-Schmidt carboxylation in the present of potassium carbonate/triethylamine(molar ratio=1:1.6),etherifing with dimethyl sulfa...