title: 4-Bromo-2H-1,3-oxazine-2,6(3H)-dione.
abstract: The title compound, C(4)H(2)BrNO(3), 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 inter-molecular hydrogen bonds, each forms a distinctive inter-molecular network. In the title compound, there are two independent mol-ecules in the asymmetric unit, with a non-crystallographic twofold screw-like relationship between them. The two indpendent mol-ecules are linked by an inter-molecular N-H⋯O hydrogen bond. In the crystal structure, this hydrogen-bonded pair is linked to translationally related mol-ecules through further inter-molecular N-H⋯O hydrogen bonds, forming one-dimensional chains along [100]. The crystal structure also has short Br⋯O=C inter-molecular contacts with distances of 2.843 (4) and 2.852 (4) Å.
authors.affiliation: Department of Chemistry, Bucknell University, Lewisburg, PA 17837, USA.
authors.forename: Damon
authors.initials: D
authors.lastname: Parrish
authors.forename: Parcharee
authors.initials: P
authors.lastname: Tivitmahaisoon
authors.forename: Gretchen M
authors.initials: GM
authors.lastname: Rehberg
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Kastner