Microwave-promoted Zirconium (IV) Chloride as an efficient, environmentally benign and recyclable homogeneous catalytic system to synthesis of bis(indolyl)methanes, in PEG as a solvent

Bhikan J. Khairnar and Bhata R

Abstract

A simple, environmentally benign and highly efficient synthesis of Bis(indolyl)methane by using Microwavepromoted Zirconium (IV) Chloride as a catalyst in PEG as a reaction solvent. Zirconium (IV) Chloride is an attractive catalyst for the electrophilic addition reaction of indole with aldehyde to afford the corresponding bis(indolyl)methane. The procedure is simple, rapid and high yielding. The catalyst exhibited a remarkable reactivity and is reusable in PEG-400 as a solvent. The ZrCl4 in PEG-400 can be reused up to 4 times without significant loss in yields and selectivity.