Electrochemical reduction of benzoyl chloride to benzil in ionic liquid BMIMBF4

A new electrochemical procedure for the electrocatalytic dimerisation of benzoyl chloride in ionic liquid, 1‐butyl‐3‐methylimidazoliumtetrafluoborate, to benzil was investigated for the first time. The electrochemical behavior of benzoyl chlorides in BMIMBF₄ was studied by cyclic voltammetry with a reduction peak at ?1.2 V (vs Ag). The electrolysis experiments were carried out in an undivided cell under mild conditions without any toxic solvents, catalysts and supporting electrolytes, creating benzil at a moderate yield (51%). The results showed that the yields were strongly affected by various factors: temperature, working potential, electrode material. Moreover, the ionic liquid was successfully recycled for this reaction. Copyright © 2011 John Wiley & Sons, Ltd.