4-Bromo-2H-1,3-oxazine-2,6(3H)-dione

Abstract

The title compound, C4H2BrNO3, is one of a series of three substituted oxauracils prepared as precursors in the preparation of 1-aza-1,3-butadienes. Although each structure has identical potential for N—H...O intermolecular hydrogen bonds, each forms a distinctive intermolecular network. In the title compound, there are two independent molecules in the asymmetric unit, with a non-crystallographic twofold screw-like relationship between them. The two indpendent molecules are linked by an intermolecular N—H...O hydrogen bond. In the crystal structure, this hydrogen-bonded pair is linked to translationally related molecules through further intermolecular N—H...O hydrogen bonds, forming one-dimensional chains along [100]. The crystal structure also has short Br...O=C intermolecular contacts with distances of 2.843 (4) and 2.852 (4) Å.