Nitrile is the important chemical raw materials and intermediates, for example, acrylonitrile is the monomer of producing polyacrylonitrile. Copolymerization with other monomers, it can be used in the production of synthetic rubber and engineering plastics. Acetonitrile is a good organic solvent. Some senior nitrile also can be used as spice. Amide is mainly used as industrial solvents. It’s used in the production of vitamins, hormones and chlordimeform in pharmaceutical industry. It’s the important raw material of intermediates in organic synthesis, engineering plastics and lubricant. Sodium percarbonate is also called the solid hydrogen peroxide and is the additive compound of sodium carbonate and hydrogen peroxide. Sodium percarbonate has non-toxic, odorless, pollution-free advantages. Moreover, sodium percarbonate also have the properties of bleaching, sterilization, cleaning and good water solubility.

 

There’re two main routes of aryl nitriles preparing aryl amides: the first one is hydrolysis of nitrile, the second one is oxidation of nitrile. This paper mainly introduces a kind of method which using sodium tungstate as catalyst, sodium carbonate or sodium carbonate-hydrogen peroxide solution as oxidant to catalyze aryl nitriles to prepare aryl amides. Operating steps are as follows:

(1) Using sodium percarbonate as oxidant, add 5mmol sodium percarbonate to the solution made of 4 ml water and 6 ml methanol. Then add 2.5mmol aryl nitrile and 0.167mmol sodium tungstate and stir for four hours under the room temperature. 

(2) Using sodium carbonate-hydrogen peroxide as oxidant, add 5mmol sodium tungstate to the solution made of 3.15ml water, 6 ml methanol and 7.5 mmol hydrogen peroxide. Then add 2.5mmol aryl nitrile and 0.167mmol sodium tungstate and stir for four hours under the room temperature. 

 

The result shows that oxidative activity of sodium carbonate-hydrogen peroxide system is higher than sodium percarbonate antioxidant system. And the generated target product selectivity of the former is up to 97% ~ 100%. Therefore, adopting a system of sodium carbonate-hydrogen peroxide as oxidant has more advantages. It will save the steps for preparation of sodium percarbonate in advance. Catalyst circulations experiments show that sodium tungstate and sodium carbonate can be separated recycle and reused. Activity and selectivity of the catalytic system remain unchanged only adding the right amount of hydrogen peroxide. This method provides a more convenient and cheaper way of green synthesis for the preparation of aryl amides. The reaction is suitable for the synthesis of a variety of aryl amides.