one stage hydrogenation of nitrobenzene to p - aminophenol

摘要

The present invention provides a single step process for the preparation of p-aminophenol by hydrogenation of nitrobenzene in presence of an aqueous acid over a mono or bimetallic catalyst at a temperature in the range of 80-120 DEG C for a period of 1 to 4 hrs. The resulting reaction mixture is extracted with toluene to separate the aqueous layer containing PAP and neutralising it stepwise with ammonia solution to recover the solid p-aminophenol.