Oxidation reduction reactions involving nitro groups in trifluoromethanesulfonic acid. Part 2. The reactions of chloromethylbenzenes with aromatic nitro Compounds

Abstract

2-Chloro-1,3-dimethylbenzene reacts with 1,4-dinitrobenzene in trifluoromethanesulfonic acid (99%) at 70 °C to give, after quenching, a 45% yield of tris(4-chloro-3,5-dimethylphenyl)methanol. Some other chloro compounds and a range of aromatic nitro compounds react in a similar manner. From isotopic labelling (¹³C, ²H), kinetic studies, and substituent effects, the reaction appears to involve a rate-determining hydride transfer from the aromatic chloro compound to the protonated nitro compound followed by a series of benzylations, debenzylations and rebenzylations accompanied by further oxidation reactions and leading finally to the corresponding triarylmethyl cations.