Electrophilic halogenation by chlorine acetate and t-butyl hypochlorite

Abstract

Heterolytic halogenations by chlorine acetate and by t-butyl hypochlorite in acetic acid have been studied; the former mainly from analysis of products and the latter both by kinetic analysis and by analysis of products. Addition processes initiated by chlorine acetate have not been formerly reported. The addition products formed by reaction between chlorine acetate and a number of different substrates are reported herein. Features of the halogenation reactions of chlorine acetate studied in this work, together with those obtained by Dr M.A. Wilson, have led to some insight into the nature of the intermediates involved and have required some revision of earlier ideas regarding the intermediates involved in molecular chlorination. In studies involving halogenation by t-butyl hypochlorite in acetic acid it has been demonstrated that reaction may occur via a direct process involving the t-butyl hypochlorite and substrate molecules or by a two-stage process in which rate-determining formation of chlorine acetate is followed by rapid reaction with the substrate. Chlorinations by t-butyl hypochlorite have been shown to be subject to catalysis by both acid and base, the acid-catalysed reaction implicating involvement by either t-BuOClH+ or ClOACH+.