Solvolysis of sulphonyl halides. VIII. Reaction of methane and ethane sulphony1 chlorides with methanol, ethanol, and mixed solvent systems

Abstract

At room temperature methanesulphonyl chloride reacts more rapidly than ethanesulphonyl chloride in solvolysis by ethanol. Their rates of reaction with methanol are approximately equal while ethanesulphonyl chloride is the more reactive in hydrolysis. The enthalpies and entropies of activation have been determined for the solvolysis of ethanesulphonyl chloride in mixtures of ethanol with benzene, carbon tetrachloride, or 2,2,4-trimethylpentane. A comparison of the excess enthalpies and entropies of mixing in the formation of these solvents with the corresponding parameters for reaction shows that the effects on reaction rate are not due merely to the modification of the initial state of the system. The effect of the polar aprotic solvent nitrobenzene on the rate of reaction with methanol is attributed to an increase in the nucleophilic tendency of the methanol rather than to solvation of the reactive centre in the transition state.