Photo-promoted oxidation of alcohols with aliphatic N-chloroamines

Abstract

Irradiation of NN-dichloro-t-butylamine (1) with alcohols, especially alcohols of benzylic type, in CCl₄was found to give the corresponding ketones and aldehydes with quantitative formation of t-butylamine hydrochloride. The photoreaction of 1-phenylethanol with (1) in cyclohexane or toluene, however, gives mainly solvent-chlorinated products together with a low yield of acetophenone. The oxidation is suppressed by HCl scavengers (triethylamine or epichlorohydrin) and accelerated by the addition of HCl irrespective of irradiation. The irradiation may induce generation of Cl· and then HCl, the latter exerting autocatalysis for the oxidation in the dark. An ionic mechanism via protonated (1) and alkyl hypochlorite is postulated and discussed.