Reactions of methazonic acid. Part V. Formation of quinazoline 3-oxides

Abstract

The product obtained from the reaction between o-aminoacetophenone and methazonic acid in 50% aqueous acetone is found to be a constant-melting mixture of 1,2-dihydro-4-methyl-2-nitromethylquinazoline 3-oxide (75%) and unchanged o-aminoacetophenone (25%). o-2′-Nitroethylideneaminoacetophenone exists mainly as the nitronic acid form in deuterochloroform or methanol. The proton magnetic resonance and ultraviolet spectra of these, and of 1,2-dihydro-2,2,4-trimethylquinazoline 3-oxide, are discussed.