Research On Pd/SiO₂ Catalytic Reduction Of N-aromatic Alkylaition Of Nitro Compounds

Catalytic hydrogenation has played an important role in industrial production especially in petrochemical industry, while the noble metal catalyst is commonly used in the hydrogenation reactions because of its high reactivity. The secondary amines have been widely utilized on industry, medicine, biochemistry and other fields, so the amine in organic synthesis have received more attention than the other functional groups compounds. Among these numerous amines, aromatic secondary amines occupy an important proportion. Combined with previous experience in our laboratory, we used the passive Ni/SiO2 catalyst in the synthesis of imine, in which the nitro compounds and aromatic aldehydes were used as the substrates. Above these bases, my work is mainly to find and synthesize a simple and efficient catalyst Pd/SiO2, and explore its applications in the secondary aromatic amine synthesis reactions.In our experimental content, we prepare catalyst Pd/SiO2, and make a series of characterization firstly. Then, we introduce an one-pot synthesis route using aromatic nitro compounds and aromatic aldehydes as substrates, and synthesize of different types of secondary aromatic amines. In the whole process of synthesis of secondary amines, we initially optimized the reaction conditions, and then under the optimal conditions, we changed the type of substrate and functional groups, finally, we have obtained good yields of most of the products. The entire experimental process is under an atmospheric pressure of hydrogen, and at 40℃. Mild reaction conditions, no environmental pollution, and the simple preparation of catalyst, all these will help this method of preparation of secondary aromatic amines expansion. Finally the catalyst is recycled and to be verified to be stable.