Amination Of Cyclohexanol And Reductive Of P-nitrophenyl Acetate Catalyst Preparation And Catalytic Performance Research

Amines are widely used organic chemical raw materials and pharmaceutical intermediates. Studies on the synthesis of amines have always been an important direction: synthesis of the new amines and the new methods for amines synthesis. In this paper, research on the amination of alcohol and the reduction of nitro compounds to amine were performed.By employing the commercialized Raney Ni and homemade Ni/Al₂O₃ and Ni/C as the catalysts, the amination of cyclohexanol was achieved. The catalytic performances of the amination reaction over different reaction conditions were also conducted. The addition of alkali into the reaction system could promote the amination reaction.Yields to the cyclohexylamine could be enhanced when a certain amount of alkali was added into the reaction system. Homemade Ni/Al₂O₃ and Ni/C were both efficient in the amination of cyclohexanol with the presence of alkali and hydrogen. Ni/C catalyst was found to be more efficient in this reaction because the reaction condition over Ni/C could be milder compared to Ni/Al₂O₃. However, when cyclohexane was employed as the solvent, Ni/Al₂O₃ showed a superior catalytic activity compared to Ni/C. Different from Ni/C, Ni Al₂O₃ was found to be deactivated under the reaction conditions. The deactivation of the Ni Al₂O₃ catalyst might be ascribed to the variation of the Al₂O₃ structure as obtained from the XRD, TEM and XPS analysis.Pd-Rh bimetallic catalyst was found to be efficient in the hydrogenation of4-nitrophenylacetic acid to produce 4-aminocyclohexylacetic acids（4-ACHAA）.Impregnation method was employed to prepare immobilized Pd-Rh bimetallic catalyst.The catalysts were characterized by XRD, XPS and TEM. The hydrogenation products were analyzed by qualitatively and quantitatively. The reaction conditions on3%Pd-5%Rh/C catalysts were also optimized in this research. A4-aminocyclohexylacetic acids yield of over 95% could be obtained with a full4-nitrophenylacetic acid conversion under the condition of 60 ℃, 8 h. After five times reuse, the catalytic activity of the Pd-Rh catalyst was still stable in this reaction andalso found to show a high activity.