The stabilities of Meisenheimer complexes. Part 40. A kinetic study of the reaction of 1-chloro-2,4-dinitrobenzene with sulphite ions in water–dimethyl sulphoxide mixtures

Abstract

Kinetic and equilibrium data are reported for the reactions of 1-chloro-2,4-dinitrobenzene with sulphite ions in dimethyl sulphoxide–water mixtures. Attack at the unsubstituted 5-position yields an observable σ-adduct and is shown to be more rapid by a factor of ca. 12 than attack at the 1-position. The latter process which yields the substitution product is likely to involve intermolecular attack of sulphite on the substrate rather than intramolecular re-arrangement of the 5-adduct.