Influence of Substituent Groups on Nuclear Reactivity in the Formation of Substituted Biphenyls by Reaction of Aromatic Diazo and Related Compounds with Aromatic Liquids. VII. p-Nitrophenylation and p-Methoxyphenylation

Abstract

Abstract N-Nitroso-p-nitroacet(anilide-14C) and N-nitroso-p-methoxyacet(anilide-14C) have been decomposed at 20.0°C in mixtures of benzene and monosubstituted benzenes C6H5X (X=NO2, Cl, OCH3, and CH3), and the reaction products have been analyzed for 4-nitro-and 4-methoxybiphenyl and isomeric 4-NO2C6H4C6H4X and 4-CH3OC6H4C6H4X by the isotope dilution method. From the results of these competitive experiments, the partial rate factors for the p-nitrophenylation and p-methoxyphenylation have been calculated (Tables I and II). The values of the partial rate factor for the meta position give a satisfactory Hammett plot with a slope of −0.81 for the p-nitrophenylation and one with a slope of +0.09 for the p-methoxyphenylation, showing that the p-nitrophenyl radical has a pronounced electrophilic character while the p-methoxyphenyl radical has little, if any, nucleophilic character.