ABSTRACT
Although nitrobenzene, nitrosobenzene and azobenzene are often observed in nitrobenzene hydrogenation, we are aware of no studies of competitive reactions. In this paper we report on the competitive hydrogenations and their mechanistic implications. Results and Discussion The hydrogenation of nitrobenzene progressed to aniline without any significant by-product formation, only trace amounts of azobenzene were formed (< 1 %) as the reaction went to completion. NMR analysis showed no detectable phenyl hydroxylamine in solution. The hydrogen uptake displayed a smooth curve and the rate of hydrogen consumption coincided with the rate of aniline production. The rate of hydrogenation of nitrobenzene to aniline was 15.5 mmol.min-1.g-1.
