甜菜碱离子液体BetaineLac催化合成氧杂蒽类化合物

摘要

本文以甜菜碱离子液体[Betaine][Lac]作为催化剂合成氧杂蒽类化合物,反应以芳香醛和5,5-二甲基-1,3-环己二酮作为底物,以少量乙醇作为溶剂,在室温下完成反应.不同取代基(吸电子基和供电子基)的芳香醛参与反应都可得到目的产物且产率达90％,产物通过核磁进行结构鉴定.反应过程具有反应时间短和操作简单的优点,此外离子液体作为催化剂可以循环使用5次以上,并保持其催化活性.%Ionic Liquid([Betaine][Lac])was found to efficiently catalyze the condensation for the synthesis of xanthenediones from aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione in ethanol to give the corresponding products under mild and environmentally benign condition.Various aryl aldehydes containing electron-withdrawing groups and electron-donating groups afforded the desired products up to 90％ yield.The products were characterized by 1 H NMR.The present procedure had the merits of short reaction time and simple reaction work up.Moreover,this catalyst could be reused for at least five consecutive runs without any loss of its catalytic activity.