International Journal of Current Microbiology and Applied Sciences |
Dichlorocyclopropanation of α- methyl styrene using phase-transfer Catalyst - A kinetic study 1K.Harikumar and 2V.Rajendran 1 Dept. of Chemistry,Sri Chandrashekarendra Saraswathi Viswa Maha Vidyalaya Deemed university 2Department of Chemistry, Pachaiyappa’s College For Men Kanchipuram, |
ABSTRACT |
In this work, a phase transfer catalyst viz., benzyltriethylammonium chloride (PTC) was assessed by observing the kinetics of dichlorocarbene addition to α- methyl styrene. The formation of the product was monitored by GLC. Dichlorocyclopropanation of α- methyl styrene catalyzed by this carried out in two-phase medium under pseudo-first-order conditions by keeping aqueous sodium hydroxide and chloroform in excess. The effect of various experimental parameters on the rate of the reaction has been studied. From the Arrhenius plot, the activation energy was found to be 16.17 kcal mol-1. Also thermodynamic parameters such as ΔS#, ΔG# and ΔH# were evaluated; based on the experimental results, a suitable mechanism is proposed. |
Keywords : Phase transfer catalysis; Dichlorocyclopropanation; α- methyl styrene; Carbenes; Interfacial mechanism. |