Pd/C催化剂催化邻硝基苯胺加氢制备邻苯二胺

卤代芳胺是重要的有机中间体,广泛应用于合成染料、农药、医药、香料及橡胶助剂等。卤代芳香硝基化合物通过液相催化加氢制备卤代芳胺的技术以其环境友好、产品质量稳定和工艺先进而受到重视。用负载型贵金属催化剂催化芳香硝基化合物选择加氢制备相应的芳胺有广泛的应用价值。采用邻硝基苯胺为原料，Pd/C为催化剂,低压催化加氢还原合成邻苯二胺，考察不同溶剂、反应压力、反应温度和反应时间对产物收率的影响。结果表明，在甲醇为溶剂、反应温度100 ℃、反应压力0.8 MPa和反应时间100 min条件下，邻苯二胺平均收率为97%。与传统硫化碱还原或铁粉化学法还原工艺相比，以甲醇为溶剂,Pd/C催化剂催化加氢法在减少废水和降低成本等方面有较大优势。

Synthesis of o-phenylenediamine from catalytic hydrogenation of o-nitroaniline over Pd/C catalyst

Aromatic haloamines are important organic intermediates which are widely used for the production of fine chemicals such as dyes,herbicides,pesticides,drugs,flavor and rubber. The selective hydrogenation process of haloaromatic nitro-compounds to the corresponding aniline catalyzed by supported noble metal catalysts in liquid phase has attracted more attention due to its advantages of benign environment,stable product quality and advanced technics. o-Phenylenediamine was synthesized by catalytic hydrogenation of o-nitroaniline over Pd / C catalyst. The effects of reaction temperature,reaction pressure,reaction time and different solvents on the product yield were investigated. The results showed that o-phenylenediamine average yield of 97% was obtained under the optimum synthesis condition as follows：reaction temperature 100 ℃,reaction pressure 0. 8 MPa,reaction time 100 min and methanol as the solvents. Compared with traditional ferrous powder or Na2 S chemical reduction methods,the catalytic hydrogenation of o-nitroaniline over Pd / C catalyst in methanol solution has more advantages with respect to reducing waste water and production cost.