Efficient synthesis of benzophenone derivatives in Lewis acid ionic liquids

Benzophenone and its derivatives were prepared via Friedel-Crafts acylation reactions using ionic liquids (ILs) of BmimCl-FeCl3, BmimCl-AICl(3) and BmimCl-ZnCl2 as dual catalyst-solvent. Among them, BmimCl-FeCl3 showed much higher catalytic activity than that observed for the other two ILs, and in conventional organic solvents. In these reaction systems, good to excellent yields (up to 97%) of acylation products were obtained in a short reaction time. This method features high yield, a simple product isolation procedure, ILs reusability and reduced waste discharge, thus rendering this catalytic system both efficient and environmentally friendly. (c) 2007 Elsevier B.V. All rights reserved