Kinetics on the Reaction of Substituted Quinolines and p-Substituted Benzoylchlorides under Various Pressures

摘要

The reaction rates of substituted quinolines (6-Clqui., qui.) with p-substituted benzoylchlorides (p-CH3, p-H, p-NO2) have been measured by conductometry in acetonitrile, and the rate constants are determined at various temperatures (10, 15, 20, 25?é) and pressures (1, 200, 500, 1000 bar). From the values of rate constants, the activation parameters (Ea, ?aV?á, ?aH?á, ?aS?á, ?aG?á) and the pressure dependence of Hammett ￥? values were determined. The rate constants increased with increasing temperatures and pressures, and are further increased to introduction to the electron acceptor substituents in substrate (p-NO2) with quinoline. The activation volume and the activation entropy are all negative. And the Hammett ￥? values are negative for nucleophile (￥?X) and positive for the substrate (￥?Y) over the pressure range studied. The results of kinetic studies for pressure and substituent show that these reactions proceed through a typical SN2 reaction mechanism and "ssociative SN2" favoring bond formation with increasing pressures.