Reaction of Sodium Borohydride.III. Reduction of Aromatic Nitro Compounds with Sodium Borohydride

Abstract

Azoxybenzene(II), azobenzene(III), and aniline(IV) were formed by the reaction of nitrobenzene(I) with sodium borohydride at 180-200° in the absence of a solvent. In this reaction, increasing concentration of sodium borohydride increased the yield of IV and decreased that of II. Similarly, reduction of o-nitrotoluene(V), m-nitrotoluene(VI), p-nitrotoluene(VII), p-methoxynitrobenzene(VIII), and p-chloronitrobenzene(IX) gave the corresponding amine and azo derivatives. In order to clarify this reaction mechanism, the same reaction of reduced derivatives, such as nitrosobenzene(XX), N-phenylhydroxylamine (XXI), hydrazobenzene(XXII), and III, was examined and all these derivatives gave IV, but its yield was poor in the reduction of III.