Kinetic solvent and temperature effects in the neutral methanolysis of chloromethyl trichloroacetate in acetonitrile–methanol solutions

Abstract

The kinetic behaviour of the neutral methanolysis of chloromethyl trichloroacetate in acetonitrile–methanol solutions over a wide temperature range has been studied. The kinetic data were compared with the available data for the neutral hydrolysis of chloromethyl dichloroacetate in acetonitrile–water solutions. It is suggested that the methanolysis of chloromethyl trichloroacetate takes place by the general base-catalysed B_AC3 mechanism, methanol acting as a general base catalyst. In contrast to the marked concentration dependence of ΔC_p^Dagger; found in the case of the neutral ester hydrolysis, it seems that for the neutral methanolysis ΔC_p^‡ remains almost unchanged over the methanol concentration range used. The difference in behaviour is interpreted in terms of the structural properties of the two solvent systems acetonitrile–methanol and acetonitrile–water.