作者：胡玉林；陆明；刘小兵

作者单位：滁州学院材料与化学工程学院南京理工大学化工学院井冈山大学化学化工学院

摘要：研究了一种有效的离子液体[DDPA][HSO4]催化Paal-Knorr反应体系,该体系能够有效地将一系列胺类化合物与2,5—己二酮反应转化为相应的吡咯化合物,产品收率都在80%以上.在超声波辐射下,[DDPA][HSO4]能较好地催化胺与2,5—己二酮反应,当胺用量为10mmol,2,5—己二酮用量为10 mmol,[DDPA][HSO4]用量为1 mmol,甲醇用量为10 mL时,收率可达81%～97%.催化剂可以方便地回收循环使用,[DDPA][HSO4]重复使用5次而催化活性基本保持不变.超声波辐射使得反应时间大大缩短(如苯胺与2,5—己二酮的反应时间由40 min缩短为5 min),反应条件温和,收率较高,操作方便,后处理简单,该工艺符合绿色化学的发展方向,具有良好的应用前景.

基金：国家重点基础研究发展计划项目(973项目,613740101)；NSFC-NSAF项目(11076017)；

关键词：Paal-Knorr反应;吡咯衍生物;离子液体;超声波;

DOI：10.16186/j.cnki.1673-9787.2013.04.014

分类号：O626

Abstract:An efficient synthesis of pyrrole derivatives by Paal-Knorr condensation reaction catalyzed by ionic liquid ［DDPA］［HSO 4 ］has been investigated and described． The treatment of a series of amines with 2，5-hexanedione in the presence of a catalytic amount of ［DDPA］［HSO 4 ］under ultrasonic radiation conditions gives the corresponding pyrrole derivatives in good to high yields，and all the yields were above 80%． Further-more，corresponding pyrrole derivatives with 81% ～97% yields were synthesized via ultrasonic-assisted Paal-Knorr condensation of amine and 2，5-hexanedione using［DDPA］［HSO4］as catalyst when the reactions were carried out using amine (10 mmol)，acetonylacetone (10 mmol)，and ［DDPA］［HSO4］(1 mmol) in CH 3 OH (10 mL) at 25 °C． The ionic liquid could be easily recycled and reused without obviously decreasing the catalytic activity． The reaction time of aniline and 2，5-hexanedione was shortened from 40 min to 5 min．Mild reaction conditions，high yields，ease of workup，easy isolation of the compounds，and excellent recycla- bility of the catalyst are the attractive features of this methodology，which is a good example of green method，and this method has shown good prospects in industrial applications．

Key words:Paal-Knorr reaction;pyrrole derivatives;ionic liquid;ultrasonic radiation