一个绿色微型有机合成实验:离子液体中3-乙酰基香豆素的合成

A Green and Micro-scale Organic Synthesis Experiment: Synthesis of 3-Acetylcoumarin in Ionic Liquid

介绍了一个在离子液体中采用串联法合成3-乙酰基香豆素的绿色有机合成实验.碱性离子液体氢氧化1-丁基-3-甲基咪唑([bmIm]OH)在合成中具有双重功能,在作为反应溶剂的同时又作为反应的催化剂使用.反应物水杨醛与乙酰乙酸乙酯首先发生克脑文格反应,生成的产物紧接着发生分子内酯交换反应得到3-乙酰基香豆素.该串联反应是一个典型的高效、绿色的合成方法,本实验内容新颖、操作简单、所需试剂价廉易得,适合作为高年级本科生有机合成实验.

The paper describes a green experiment for the synthesis of 3-acetylcoumarin in ionic liquid via cascade reactions.A basic ionic liquid,1-butyl-3-methyl-imidazolium hydroxide（OH）,plays a dual role in the synthesis,for it serves not only as the solvent but also as the catalyst for the reaction.3-Acetylcoumarin was formed via the cascade reactions of Knoevenagel reaction between salicylic aldehyde and ethyl acetoacetate and the consequent intramolecular transesterification reaction.The present procedure is an efficient and green synthesis method.The experiment is novel and simple,and the reagents required are cheap and readily available.It is very suitable to be used as an organic synthesis experiment for senior college students.