(E)-1-(5-Bromo-2-hydroxyphenyl)-3-[4-(dimethylamino)phenyl]prop-2-en-1-one

In the title compound, C17H16BrNO2, the two benzene rings make a dihedral angle of 7.4 (3)°; the hydroxy group links to the carbonyl group via an intramolecular O—H⋯O hydrogen bond. In the crystal, weak C—H⋯O interactions link the molecules into a supramolecular chain running along the c axis.

In the title compound, C 17 H 16 BrNO 2 , the two benzene rings make a dihedral angle of 7.4 (3) ; the hydroxy group links to the carbonyl group via an intramolecular O-HÁ Á ÁO hydrogen bond. In the crystal, weak C-HÁ Á ÁO interactions link the molecules into a supramolecular chain running along the c axis.   Table 1 Hydrogen-bond geometry (Å , ). Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
The asymmetric unit is composed of one whole amine molecule. The two benzene rings are nearly coplanar and twisted from each other by a dihedral of 7.4 (3)°. The hydroxy H2 atom was involved in intramolecular O-H···O hydrogen bonds interaction (Table 1 and Fig. 1).

Experimental
The title compound (2.0 mmol) was solved in 50 mL methanol. Then the solution was evaporated slowly in the air. Red block crystals suitable for X-ray analysis were obtained after one week.

Refinement
All H atoms attached to C atoms were fixed geometrically and treated as riding with C-H = 0.95 Å (aromatic) and C-H = 0.98 Å (methyl) with U iso (H) = 1.2U eq (C) and U iso (H) = 1.5U eq (methyl). H atoms bonded to O atom was located in difference Fourier map and restrained with the H-O = 0.82 (2) Å. In the last stage of refinement they were treated as riding on the O atom with U iso (H) = 1.5U eq (O).  Molecular view of the title compound with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.