RUTHENIUM-TPPTS CATALYZED REDUCTlON OF NITROBENZENE TO ANILINE——A HIGHLY SELECTIVE WATER-SOLUBLE CATALYST SYSTEM

The ruther ium catalvst complex formed from RuCl·3HO andthe water-soluble ligand tris-（sodium m-sulfophenyl）phosphine, TPPTS, hasbeen examined as a catalyst for the reduction of nitrobenzene to anilineunder water gas shift conditions. The reactions, which were conducted inaqueous methanol. were studied as a function of CO pressure and addedamine base The major product observed over the temperature range of100～150℃ was aniline （>90% yield abovc 130℃ ）, with only minor amountsof the corresponding carbamate PhNHCOMe（<3%） and formanilide（<4%）being observed. Of the several amine bases examined in this reaction, EtNhas been found to be superior in promoting the fastest rate of nitrobenzenereduction. Replacement of methanol by either THF or xylenes led to a drastic retardation in the amount of aniline produced.