(2E)-3-(2-Bromophenyl)-1-(5-bromothiophen-2-yl)prop-2-en-1-one

The asymmetric unit of the title compound, C13H8Br2OS, contains two molecules, in which the dihedral angles between the thiophene and benzene rings are 10.5 (3) and 33.2 (4)°. There are no significant directional interactions in the crystal.

The asymmetric unit of the title compound, C 13 H 8 Br 2 OS, contains two molecules, in which the dihedral angles between the thiophene and benzene rings are 10.5 (3) and 33.2 (4) . There are no significant directional interactions in the crystal.  conformation obtained in this bound state may provide good rationality in drug design study. As a part of our effort in designing lead compound for human aldose reductase inhibiton we are interested in studying the crystal structure conformation of (2E)-1-(5-bromothiophen-2-yl)-3-[4-(dimethylamino) phenyl]prop-2-en-1-one. In our docking studies the title chalcone has shown good binding affinity with dock score -9.490027 calculated by using GLIDE scoring (Thomas et al., 2004) function from Schrodinger 9.2v molecular modeling suite.

Experimental
A mixture of 2-acetyl-5-bromothiophene (0.01 mole) and 2-bromobenzaldehyde (0.01 mole) were stirred in ethanol (30 ml) and then an aqueous solution of potassium hydroxide (40%, 15 ml)was added to it. The mixture was kept over night at room temperature and then it was poured into crushed ice and acidified with dilute hydrochloric acid. The precipiteted chalcone was filtered and crystallized from ethanol as colourless prisms.

Refinement
All H atoms were positioned at calculated positions C-H = 0.93 Å for aromatic H and refined using a riding model with U iso (H) = 1.2U eq (C)for aromatic H. Attempts to model non-merohedral twinning resulted in no improvement.  The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
Packing of the molecules.

(2E)-3-(2-Bromophenyl)-1-(5-bromothiophen-2-yl)prop-2-en-1-one
Absolute structure: Flack (1983), 2846 Friedel pairs Flack parameter: 0.000 (13) Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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.