Synthesis Of 2-methyl-4-methoxylaniline By Pt/C Catalytic Hydrogenation

2-methyl-4-methoxylaniline is an important intermediate in fine chemical industries and mainly used for the synthesis of dyes, pharmaceuticals, rubbers and agricultural chemicals. 2-methyl-4-methoxylaniline was mainly synthesized by catalytic hydrogenation with o-nitrotoluene using a noble metal catalyst.This paper introduced a new method aiming to improve the stability of Pt/C in the hydrogenation cycles for the synthesis of 2-methyl-4-methoxylaniline, and thus reduced the cost of catalytic hydrogenation technology. Pt/C catalyst was prepared by impregnation method. The effects of raw materials ratio, reaction temperature, catalysts on the conversion of o-nitrotoluene and the selectivity of 2-methyl-4-methoxylaniline were investigated under 1atm of H2. It was found that 3% Pt/C catalyst was suitable for this reaction. The deactivation mechanism of catalyst was explored by BET, XRD, XRF techniques. The deactivation of Pt/C might be caused by in situ formed intermediates. The regenerative catalyst which was rinsed with methanol showed obviously higher stability in the hydrogenation cycles, and the cost for the synthesis of 2-methyl-4-methoxylaniline was greatly reduced.