氧气液相氧化邻硝基甲苯制取邻硝基苯甲醛

以有机胺为溶剂，锰盐为催化剂，氧气液相氧化邻硝基甲苯制取邻硝基苯甲醛。研究了强碱氢氧化钾加入量和溶剂等对反应的影响，发现随着碱浓度的增加，邻硝基甲苯的转化率增加，邻硝基苯甲醛的收率先增后降。与间硝基甲苯的氧化结果比较表明强碱的助催化作用表现在它能从邻硝基甲苯侧链甲基上夺取一个质子使之形成碳阴离子，碳阴离子在氧气的氧化下生成产物。研究溶剂对反应的影响发现，2－甲氧基乙胺、丙胺、吗啉等有机胺类配位溶剂有利反应的进行，在甲醇等质子溶剂中不发生所希望的氧化反应。

Preparation of o-NBA via Liquid Phase Oxidation of o-MNT with Oxygen

o-Nitrobenzaldehyde was prepared via liquid phase manganese catalyzed oxidation of o-nitrotoluene in organic amine solvent. The effect of strong base, KOH, was studied and it was found that the conversion of o-nitrotoluene increased if the amount of KOH increased. The dependence curve of the yield of o-NBA on the amount of KOH used reaches a maximum at a ratio value of 0.6 of KOH over CH 3OH. The oxidation of m-nitrotulene in the same condition shows that the conversion of m-MNT was almost independent of the amount of KOH used, which suggests that the oxidation of o-MNT in the presence of KOH proceeds via an intermediate of benzyl anion. It was also found that the reaction proceeds smoothly in organic amine solvents, such as 2methoxyethylamine, which are capable to form complex with the catalytic metal manganese. In solvents with active proton, such as methanol, no desired oxidation takes place.