Kinetic study of dichlorocyclopropanation of 4-vinyl-1-cyclohexene by a novel multisite phase transfer catalyst

In this work, the dichlorocyclopropanation of 4-vinyl-1-cyclohexene catalyzed by a new novel phase transfer catalyst was carried out in an alkaline solution/chloroform two-phase medium. This new synthesized phase transfer catalyst, 1,4-bis(triethylmethylammonium)benzene dichloride (DC-X), which possesses two-site activity, was obtained from the reaction of ,′-dichloro-p-xylene and triethylamine. This new novel phase transfer catalyst exhibits higher reactivity than those of the other quaternary ammonium salts. The reaction of chloroform and alkali was carried out at the interface to generate dichlorocarbene which can further react with 4-vinyl-1-cyclohexene to produce mono-dichlorocyclopropane and bis-dichlorocyclopropane products. Rational mechanism of the dichlorocyclopropanation is proposed according to the experimental evidence. The reaction follows a pseudo-first-order rate law. Kinetics of the reactions such as: effect of the catalysts, agitation speed, temperature, alkaline concentration, amount of DC-X catalyst, amount of 4-vinyl-1-cyclohexene (reactant) and volume of chloroform (organic solvent) on the reaction rate were investigated in detail. Peculiar phenomenon for the dependence of the reaction rate on the amount of DC-X catalyst is explained satisfactorily.