Transesterification of dimethyl carbonate with phenol using Bronsted and Lewis acidic ionic liquids

Transesterification reaction of dimethyl carbonate with phenol to methylphenyl carbonate and diphenyl carbonate using dibutyltin oxide catalyst in conjunction with Bronsted and Lewis acidic ionic liquids was studied It was observed that the use of ionic liquids significantly enhances the yield of diphenyl carbonate The ionic liquid having p-toluenesulfonate as anion and metal halide (e g ZnCl2) as Lewis acid precursor exhibited higher activity and selectivity for diphenyl carbonate formation Furthermore the Bronsted and Lewis acidity of ionic liquids was measured by IR spectroscopy using pyridine as a probe and their Lewis acidity order was also determined (C) 2010 Elsevier B V All rights reserved