Sulphuryl chloride as an electrophile for aromatic substitution

Abstract

The reactions of sulphuryl chloride with anisole and some methyl-substituted anisoles have been studied kinetically in chlorobenzene as solvent. The reactions have the kinetic form –d[SO₂Cl₂]/dt=k₂[ArH][SO₂Cl₂], and give almost exclusively the products of nuclear chlorination. The rate is powerfully facilitated by the electron-releasing effect of methyl groups in the nucleus. The results are interpreted as indicating that the reactions are heterolytic, and probably involve electrophilic attack by molecular sulphuryl chloride.