钨酸钠催化芳香腈高选择性氧化制备芳香酰胺  

Preparation of Aryl Amides by Sodium Tungstate-Catalyzed Selective Oxidation of Aryl Nitriles

作　　者：杨敏[1] 李敏[1] 郑宏杰[1] 李贤均[1] 

机构地区：[1]四川大学化学学院有机金属络合催化研究所,绿色化学与技术教育部重点实验室(四川大学),四川成都610064

出　　处：《催化学报》2005年第3期175-177,共3页

摘　　要：The preparation of aryl amides by selective oxidation of aryl nitriles using sodium tungstate as catalyst and sodium percarbonate or sodium carbonate-hydrogen peroxide as the oxidant in a methanol and water solution was studied. Aryl nitriles were converted to aryl amides with very high selectivity of 95%～100% at room temperature. The reactivity of aryl nitriles decreased with increasing their branched chain length. In the oxidation of tolunitriles, the oxidation rate of p-tolunitrile and m-tolunitrile was very fast, but the oxidation rate of o-tolunitrile was very slow. The oxidation rate of p-haloid aryl nitriles and p-nitro aryl nitrile decreased in the order p-nitrobenzonitrile >p-chlorobenzonitrile>p-bromobenzonitrile, while the selectivity for aryl amides was maintained at a high level of 98%～100%. The comparison of the two oxidants showed that when sodium carbonate-hydrogen peroxide was used as oxidant, the oxidation rate and selectivity were better than that when percarbonate was used. The sodium tungstate catalyst and carbonate can be reused and the catalytic activity and selectivity did not change if a suitable amount of hydrogen peroxide was supplied. This work provides a convenient method for the preparation of aryl amides from aryl nitriles under very mild reaction conditions.The preparation of aryl amides by selective oxidation of aryl nitriles using sodium tungstate as catalyst and sodium percarbonate or sodium carbonate-hydrogen peroxide as the oxidant in a methanol and water solution was studied. Aryl intriles were converted to aryl amides with very high selectivity of 95% similar to 100% at room temperature. The reactivity of aryl nitriles decreased with increasing their branched chain length. In the oxidation of tolunitriles, the oxidation rate of p-tolunitrile and m-tolunitrile was very fast, but the oxidation rate of o-tolunitrile was very slow. The oxidation rate of p-haloid aryl mtriles and p-nitro aryl nitrile decreased in the order p -nitrobenzonitrile > p-chlorobenzonitrile > P-bromobenzonitrile, while the selectivity for aryl amides was maintained at a high level of 98% - 100%. The comparison of the two oxidants showed that when sodium carbonatehydrogen peroxide was used as oxidant, the oxidation rate and selectivity were better than that when percarbonate was used. The sodium tungstate catalyst and carbonate can be reused and the catalytic activity and selectivity did not change if a suitable amount of hydrogen peroxide was supplied. This work provides a convenient method for the preparation of aryl amides from aryl nitriles under very mild reaction conditions.

关 键 词：钨酸钠 过碳酸钠 碳酸钠 过氧化氢 芳香腈 催化氧化 芳香酰胺 

分 类 号：O625.6[理学—有机化学]