The title compound, C4H7N3O2, formed by oxidation of the parent 4,5-di
hydro-5,5-dimethyl-1,2,4-triazol-3-one consists of a planar five-membe
red ring with the two O atoms displaced slightly on the same side of t
he ring. Both the azoxy moiety and the amide N atom are involved in co
njugation with the carbonyl group. The molecules in the crystal associ
ate into centrosymmetric double-hydrogen-bonded dimers.