Aromatic Substitutions by Aryl Radicals V

Abstract

The reaction of N-nitrso-p-nitroacetanilide with anisole at room temperature yielded 2-methoxy-4′-nitrobiphenyl, 3-methoxy-4′-nitrobiphenyl and 4-methoxy-4′-nitrobiphenyl in a molar ratio of 11.8: 1: 2.2. From the result of a competitive run in a mixture of anisole and benzene, the partial rate factors of the ortho, meta and para positions of anisole towards the p-nitrophenyl radical are calculated to be 4.9, 0.4 and 1.7 respectively, the reactivity of one position of benzene being taken as unity. Similar partial rate factors (o:m: p=3.3: 0.4: 1.6) for anisole were obtained from the result of an experiment at 94°C using p-nitrobenzoyl peroxide as a p-nitrophenyl radical source. The decomposition of anisoyl peroxide in a mixture of nitrobenzene and benzene at 92-5°C yielded 4-methoxybiphenyl, 4-methoxy-2′-nitrobiphenyl, 4-methoxy-3′-nitrobiphenyl and 4-methoxy-4′-nitrobiphenyl, from whose molar ratio the partial rate factors of the ortho, meta and para positions of nitrobenzene towards the p-methoxyphenyl radical were found to be 4.6, 0.2 and 6.2 respectively.