Selective Liquid-Phase Hydrogenation of a Nitro Group in Substituted Nitrobenzenes over Au/Al O Catalyst in a Packed-Bed Flow Reactor.

A series of substituted nitrobenzenes with the general formula XC H NO (X=Cl, CH=CH , or C(O)CH ) dissolved in toluene were reduced with hydrogen over the 1.9 % Au/Al O catalyst at 60-110 °C and 10-20 bar in a three-phase packed-bed reactor operating in up-flow mode. Under these conditions, hydrogenation of isomeric ClC H NO gives exclusively chloroanilines.