Synthesis of Diphenylmethane from Benzene and Paraformaldehyde Catalyzed by Acidic Ionic Liquids.

Condensations of benzene or toluene, xylene and paraformaldehyde to diphenylmethane (DPM) or its derivatives were performed using acidic ionic liquids Et3NHCl–AlCl3, Et3NHCl–FeCl3, Et3NHCl–ZnCl2, Et3NHCl–CuCl2, Et3NHCl–CuCl, Et3NHCl–SnCl2 as catalysts. The catalytic activity of Et3NHCl–AlCl3 proved to be superior to that of other catalysts for the condensation of benzene and paraformaldehyde, giving 92.4% conversion of HCHO and 76.1% selectivity to diphenylmethane at 80 °C and atmospheric pressure. The effect of various reaction conditions on the reaction and reaction kinetics of DPM synthesis were explored. [ABSTRACT FROM AUTHOR]