A Study of Pd/C Catalysts in the Liquid-phase Hydrogenation of 1,3,5-Trinitrobenzene and 2,4,6-Trinitrobenzoic Acid. Selection of Hydrogenation Conditions for Selective Production of 1,3,5-Triaminobenzene

The liquid-phase hydrogenation of aromatic trinitro compounds was studied at atmospheric and elevated pressure and a temperature of 50–70 °C. It was shown that at atmospheric pressure, irrespective of the solvent type (water or acetic anhydride), a complete reduction of the nitro groups of 2,4,6-trinitrobenzoic acid to amino groups does not occur; the intermediate products of hydrogenation and the products of secondary transformations are present in the solution. An increase in pressure to 5 bars ensures a complete hydrogenation of 2,4,6-trinitrobenzoic acid and 1,3,5-trinitrobenzene with the formation of 1,3,5-triaminobenzene.