Aldehydes amine oxidations, manganese dioxide

Carboxylic amides. Gilman has extended the procedure of Corey et at. (2, 261) for oxidation of allylic alcohols to carboxylic esters to the preparation of carboxylic amides. Thus oxidation of aromatic and a,/ -unsaturated aldehydes with Mn02 in the presence of sodium cyanide and an amine gives the corresponding carboxylic amides in high yield. In the absence of sodium cyanide, high yields of nitriles are formed from aldehydes, ammonia, and manganese dioxide. 

The oxidation of aldehydes in the presence of amines occurs at low temperatures with nickel perox-ide. Similarly, the oxidation of aromatic aldehydes with manganese dioxide or ruthenium chloride in the presence of sodium cyanide and an amine leads to the corresponding amides. 

A similar reaction was reported by Meth-Cohn and Suschitzky [62], who obtained aldehydes from the aerobic oxidation of amines in neutral solution in the presence of a manganese dioxide catalyst. 

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