Ultrasound-assisted three-component synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones in water.

Indium(III) chloride was found to be an efficient catalyst for the synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones by one-pot, three-component reaction of dimedone, 1H-pyrazol-5-amines and isatins in water under ultrasonic irradiation. The advantages of this method are the use of a readily available catalyst, easy workup, excellent yields, and the use of water as a solvent that is considered to be relatively environmentally benign. Copyright 2009 Elsevier B.V. All rights reserved.