催化加氢制备3-氨基-4-甲氧基乙酰苯胺

以高速淬冷法制备的Ni-Mo-Al合金为前体、经活化制得的改性骨架镍为催化剂,催化3-硝基-4-甲氧基乙酰苯胺(NMA)液相加氢制备3-氨基-4-甲氧基乙酰苯胺(AMA)。考察了催化剂用量、反应温度、反应压力对反应的影响,优化了反应条件。在以甲醇为溶剂、60℃、1.0MPa、催化剂用量0.3g(m(催化剂)∶m(NMA)=1∶10)的条件下反应40min,NMA转化率为100%,AMA选择性达99.9%。催化剂循环使用44次,稳定性良好。对该反应的动力学研究结果表明,在NMA浓度低于0.71mol/L时,该反应对于NMA的浓度宏观表现为零级反应;当反应压力为0.5～2.5MPa时,该反应对于反应压力宏观表现为一级反应;该反应的表观活化能约为52kJ/mol。

Preparation of 3-Amino-4-Methoxy-Acetanilide from 3-Nitro-4-Methoxy-Acetanilide by Catalytic Hydrogenation

Modified skeletal Ni catalyst prepared from rapidly quenched Ni-Mo-Al alloy was used in the liquid-phase selective hydrogenation of 3-nitro-4-methoxy-acetanilide (NMA) to 3-amino-4-methoxy-acetanilide (AMA). Effects of catalyst dosage,reaction temperature and pressure on the reaction were investigated. Under optimized conditions:60 ℃,1.0 MPa,catalyst doasge 0.3 g (m(catalyst)∶m(NMA) =1 ∶10) and methanol as solvent,conversion of NMA is 100% and selectivity to AMA reaches 99.9% in 40 minutes. The catalyst was reused for 44 times and exhibited excellent catalytic activity and stability. Kinetics of the reaction was also investigated. The reaction is zero order with respect to concentration of NMA in the range of 0-0.71 mol/L,and first order to hydrogen pressure in the range of 0.5-2.5 MPa. Apparent activation energy of the reaction is about 52 kJ/mol.