[BMIm]HSO۴ as a Green and Highly Efficient Catalyst for One-pot Synthesis of ۳-Substituted Indoles under Ultrasound Irradiation

A practical and green synthesis of ۳-substituted indoles is reported via three-component coupling reaction of indoles, aldehydes and N-methylaniline in the presence of the acidic ionic liquid ۱-butyl-۳-methylimidazolium hydrogen sulfate ([BMIm]HSO۴) under ultrasound irradiation at room temperature. The significant features of this procedure are high yields of the products, simple work-up, operational simplicity and non-toxicity of the catalyst. Moreover, [BMIm]HSO۴ is successfully reused for four cycles without significant less of activity. Keywords. Indoles, N-methylaniline, Aldehyde, Ionic liquid.

Keywords:

Indoles , N-methylaniline , Aldehyde , Ionic Liquid