L-脯氨酸催化的香豆素-3-羧酸的'一锅法'合成

摘要

Ethyl coumarin-3-carboxylate from different substituted salicylaldehydes with diethyl malonate catalyzed by L-proline in DMSO could be effectively synthesized. After that,coumarin-3-carboxylic acids could be prepared by hydrolysis using KOH as the base and then acidification using HCl as acid in"one-pot"reaction. This method had the advantages such as easy to operate,conven-ient work-up,short reaction time,high reaction yield,cheap catalyst and solvent,and environmentally benign.%用二甲亚砜为溶剂,L-脯氨酸为催化剂,能简便高效地催化水杨醛与丙二酸二乙酯发生Knoevenagel缩合反应得到香豆素-3-羧酸乙酯,之后加入氢氧化钾进行水解,浓盐酸酸化得到香豆素-3-羧酸.本方法具有易于操作,反应收率较高,后处理方便,反应时间短,催化剂和溶剂廉价易得,绿色环保等优点.