Heterocycles in organic synthesis. Part 40. Oxidation of 2,4,6-triarylpyridinium betaines and 2,4,6-triarylpyridinium perchlorates by hydrogen peroxide

Abstract

N-(2-Oxidophenyl and 2-oxido-1-naphthyl)-2,4,6-triarylpyridiniums are oxidised by hydrogen peroxide to mixtures of tetra-arylpyrroles and 3-oxidopyridiniu m betaines, whereas 2,4,6-triarylpyridinium salts and alkaline hydrogen peroxide give β- amino- and β-aroylamino-chalcones.