Synthesis 2003(4): 0555-0559
DOI: 10.1055/s-2003-37643
PAPER
© Georg Thieme Verlag Stuttgart · New York

Organic Reactions in Ionic Liquids: Knoevenagel Condensation Catalyzed by Ethylenediammonium Diacetate

Ce Sub, Zhen-Chu Chen*a,b, Qin-Guo Zhengc
a Ningbo Institute of Technology, Zhejiang University, Ningbo, 315104, P. R. China
b Department of Chemistry, Zhejiang University (Xi-xi campus), Hangzhou, 310028, P. R. China
e-Mail: zhenchuc@mail.hz.zj.cn;
c Pharmaceutical Sciences Research Institute, Aston University, Aston Triangle, Birmingham B4 7ET, UK
Further Information

Publication History

Received 25 October 2002
Publication Date:
07 March 2003 (online)

Abstract

The moisture and air stable ionic liquids 1-butyl-3-methylimidazonium tetrafluoroborate [bmim]BF4 and 1-butyl-3-methylimidazonium hexafluorophosphate [bmim]PF6 were used as ‘green’ recyclable alternatives to volatile organic solvents (VOCs) for ethylenediammonium diacetate (EDDA) catalyzed Knoevenagel condensation between aldehydes or ketones with active methylene compounds. Both aldehydes and ketones gave satisfactory results. The ionic liquids containing catalyst EDDA were recycled several times with no decreases in yields and reaction rates. In the case of 2-hydroxybenzaldehyde, the reactions led to the formation of 3-substituted coumarins under standard reaction conditions.