The Reactivity of Selenium Dioxide Towards Aromatic Aldehydes Hydrazones, Azines and Phenylhydrazones: Carbonyl Regeneration and a New One‐Pot Oxidation of Aldehydes to Aromatic Acids

Selenium dioxide is a mild oxidizing reagent able, in hot D. M. F. solution, to regenerate arylaldehydes from their hydrazones and azines. The same experimental conditions in the case of phenylhydrazones of aromatic aldehydes yield the corresponding substituted benzoic acids. In this respect the behaviour of SeO2 differs from that of benzeneseleninic anhydride.