Aminolysis of substituted phenyl thiolacetates by imidazole

Abstract

A series of <i>m</i>- and <i>p</i>-substituted phenyl thiolacetates have been prepared. The kinetics of aminolysis of these acetates by imidazole have been followed at 20^ᵒC and an ionic strength of 0.1 mol dm^-3 at different <i>p</i>H in water containing traces of dioxan. The non-linear Hammett plot and the nonlinear plot between log <i>k</i>₂ and log <i>k₍</i>_OH) indicate the possibility of two types of mechanism, viz., unassisted nucleophilic substitution for the compounds having electron-withdrawing groups in the leaving moiety and general acid-assisted nucleophilic substitution for the compounds having electron-releasing groups in the leaving moiety.