Fluorescence characteristics of azaperone and of an azaperone mononitrogen oxide

The structure elucidation of the compound isolated after peroxide treatment of azaperone is described. A mononitrogen oxide was formed at the piperazine N1 atom after reaction with excess hydrogen peroxide. The fluorescence characteristics of derivative were examined and compared with the native fluorescence capacities of the azaperone base; both were identical, depending on the solvent nature. The phenomenon is explained by the fact that the fluorescent properties of the azaperone molecule are principally produced by its ortho-nitrogen substituted pyridine nucleus.