The specific rates of solvolysis of α, p-dichloroanisole (chloromethyl p-chlorophenyl ether, 1) have been measured conductimetrically in a variety of hydroxylic solvents. In three typical solvents, at 25.0 °C, the rate is 20–45 times greater than for the corresponding sulfide. In a comparison with the solvolysis of a substrate with an alkyl group replacing the aryl group, chloromethyl ethyl ether (2), at −10.0 °C in four typical solvents, 1 reacted considerably more slowly than 2, by a little over four orders of magnitude. An extended Grunwald–Winstein equation treatment of the specific rates of solvolyses in 24 solvents at 25.0 °C leads to an l value of 0.68 ± 0.04 and an m value of 0.59 ± 0.03 (l/m = 1.15). Appreciable nucleophilic assistance in the progress to the transition state is indicated and either nucleophilic solvation to an ionisation process or a loose SN2 transition state with extensive bond-breaking accompanied by a smaller degree of bond-making lead to an appropriate transition state.
