Choline Chloride/Urea Ionic Liquid Catalyzed a Convenient One-Pot Synthesis of Indole-3-propanamide Derivatives

Abstract

A sequential three-component reaction of aromatic aldehydes with Meldrum's acid and N-methyl indole in the presence of choline chloride/urea ionic liquid as green catalyst has been described. In this one-pot multicomponent reaction, a series of indole-3-propanamide derivatives were synthesized with good to excellent yields. This methodology shows several advantages including fast reaction, easy isolation, operational simplicity that make it a useful and attractive option for the library generation of indole-3-propanamides (5a–l) for drug discovery.

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GRAPHICAL ABSTRACT

Keywords:

• Choline chloride/urea
• indole-3-propanamides
• Meldrum's acid
• multicomponent reaction

ACKNOWLEDGMENTS

We are thankful to the Department of Postgraduate Studies and Research in Chemistry, Kuvempu University, Shankaraghatta, for providing laboratory facilities and to the Indian Institute of Science, Bangalore, for providing spectral data.

Notes

Note. IL, choline chloride/urea; NR; no reaction; TEA; triethyl amine; DIPEA; diisopropyl ethyl amine.

^a All reactions were carried out at reflux temperature.

^b Isolated yields.

^a All reactions were carried out at reflux temperature.

^b Isolated yields.