Ru-catalyzed arene hydrogenation: a highly efficient and selective process for preparing trans-trans isomer of 4,4'-diamino-dicyclohexy

摘要

The selective hydrogenation of 4,4'-methylenedianiline(MDA) over Ru/y-Al_2O_3 was investigated in the presence of diamine and base. Under the optimum conditions: the reaction temperature of 448K, H_2 pressure of 1100 psig , and reaction time of 5h, the conversion of 4,4'-methylenedianiline was close to 100% and the selectivity to trans-trans isomer of 4.4'-diamino-dicyclohexy was less than 20%.