Structural Characterization of a Benzoxazinophenoxazine Formed as a By-Product During the Synthesis of a 3-Amino-N,N-dimethylsalicylamide

Several highly colored by-products were observed chromatographically during the synthesis of 3-amino-N,N-dimethylsalicylamide. One of these, an oxidative dimerization products, bis-(N,N-dimethylcarboxamido)-aminophenoxazinone, was previously isolated and characterized. A tris-(N,N-dimethylcarboxamido)-benzoxazino[3,2-b]phenoxazine, presumably a higher oxidation or further reaction product of the previously isolated and characterized 2-amino-3H-phenoxazin-3-one, has also been isolated and characterized by mass spectrometry and multinuclear NMR methods. We now wish to communicate the results of that structure characterization effort.