4-(4-Bromo­phen­yl)-7,7-dimethyl-2-methyl­amino-3-nitro-7,8-di­hydro-4H-chromen-5(6H)-one including an unknown solvate

In the title compound, C18H19BrN2O4, the chromene unit is not quite planar (r.m.s. deviation = 0.199 Å), with the methyl C atoms lying 0.027 (4) and 1.929 (4) Å from the mean plane of the chromene unit. The six-membered carbocyclic ring of the chromene moiety adopts an envelope conformation, with the dimethyl-substituted C atom as the flap. The methyl-amine and nitro groups are slightly twisted from the chromene moiety, with C-N-C-O and O-N-C-C torsion angles of 2.7 (4) and -0.4 (4)°, respectively. The dihedral angle between the mean plane of the chromene unit and the benzene ring is 85.61 (13)°. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif, which stabilizes the mol-ecular conformation. In the crystal, mol-ecules are linked via N-H⋯O hydrogen bonds, forming hexa-gonal rings lying parallel to the ab plane. A region of disordered electron density, most probably disordered ethanol solvent mol-ecules, occupying voids of ca 432 Å(3) for an electron count of 158, was treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. Their formula mass and unit-cell characteristics were not taken into account during refinement.