Intrinsic catalytic activity of Brønsted acid ionic liquids for the synthesis of triphenylmethane and phthalein under microwave irradiation

Abstract

A microwave-irradiated, ionic liquid-catalyzed, solvent-free method for the synthesis of triphenylmethane and a phthalein derivative has been developed from different aldehydes or anhydrides and substituted phenols or N,N-diaryl amines, respectively. Short reaction time, ambient reaction conditions, recyclability of catalyst, simple work up and high yields are some of the striking features of the present protocol. The immobilized catalyst could be easily recovered by simple filtration and recycled for up to four cycles without significant decrease in the catalytic activity.