Molecular interactions with CO2 for controlling the regioselectivity of liquid phase hydrogenation of 2,4-dinitroaniline.

The catalytic hydrogenation of 2,4-dinitroaniline using a 0.5 wt% Pt/TiO2 catalyst was investigated in a multiphase medium of tetrahydrofuran (THF) pressurized by CO2 at different pressures and at 323 K. When CO2 pressure was increased, the overall rate of hydrogenation simply decreased but the selectivity to the desired product of 4-nitro-1,2-phenylenediamine increased.