Pd/C催化氢化芳香族硝基化合物合成芳胺

Synthesis of Aromatic Amines by Pd/C Catalytic Hydrogenation Aromatic Nitro-compounds

以5%Pd/C为催化剂,芳香族硝基化合物在温和条件(30℃,H2/0.1 MPa)下还原成芳胺。研究了芳环上的取代基对催化加氢反应的影响。结果表明:对位取代的芳硝基化合物的加氢反应速率为:H>CH3>CO2CH3>CF3>F>OCH3;间位取代芳硝基化合物加氢反应速率为:H>CH3>CF3>F>CO2CH3>OCH3>CN;邻位取代芳硝基化合物加氢反应速率为:H>CF3>CH3>OCH3>F>CO2CH3>CN。

A series of aromatic amines compounds were synthesized by catalytic hydrogenation, using aromatic nitro-compound as the materials and 5% Pd/C as the catalyst under mild conditions（30 ℃, H2/0.1 MPa）. The effects of substituents of aromatic nitro compounds on the hydrogenation reactivities were investigated. The results showed that the type and position of substituents had a considerable effect on hydrogenation reaction. Hydrogenation rates of para-substituted nitrobenzenes were compared and the following order were observed： H 〉 CH3 〉 CO2CH3 〉 CF3 〉 F 〉 OCH3. The reaction rate of meta-substituted nitrobenzenes decreased in the following order： H 〉 CH3 〉 CF3 〉 F 〉 CO2CI-I3 〉 OCH3 〉 CN. The reaction rate of ortho-substituted nitrobenzenes decreased in the following order： H 〉 CF3 〉 CH3 〉 OCH3 〉 F 〉 CO2CH3 〉 CN.