4-[(Dimethylamino)methylidene]-2-(4-nitrophenyl)-1,3-oxazol-5(4H)-one

The title molecule, C12H11N3O4, is essentially planar, the r.m.s. deviation for all non-H atoms being 0.068 Å. An intramolecular C—H...N hydrogen bond occurs. The crystal packing is dominated by π–π interactions [shortest centroid–centroid distance = 3.6312 (16) Å], which lead to supramolecular chains that are linked into a three-dimensional network via C—H...O contacts. The crystal was found to be a non-merohedral twin (twin law −1 0 0/0 −1 0/ 0.784 0 1), the fractional contribution of the minor component being approximately 22%