超临界法制备离子液体1-丁基-3-甲基咪唑溴化盐

Preparation of 1-butyl-3-methylimidazolium bromide via a supercritical fluid route

以超临界CO2为溶剂,由N-甲基咪唑和溴代正丁烷制备了标题化合物,并采用超临界CO2萃取的方法纯化产物。考察了超临界CO2温度、压力和时间对反应产率及对未反应的溴代正丁烷的萃取率的影响。产物的结构和纯度通过1HNMR表征。

A green process for preparing the key ionic liquid precursor, 1-butyl-3-methylimidazolium bromide （ [Bmim] Br）, was developed. With supercritical carbon dioxide （ scCO2 ） used as the solvent, [ Bmim] Br was prepared effectively via the reaction of 1- methylimidazole and 1-bromobutane. The residual reactants could be,in situ, removed completely using scCO2 extraction after the reaction to purify the product. The effect of pressure, tempera- ture, and time on the yield of [ Bmim ] Br and on the extraction efficiency for the residual reactant （1-bromobutane） was investigated. The structure and purity of the final product were characterized by means of 1^HNMR spectroscopy.