2-Bromo-2-(5-bromo-1H-1,2,4-triazol-1-yl)-1-(2,4-difluorophenyl)ethanone

In the title compound, C10H5Br2F2N3O, the mean planes of the benzene and triazole rings form a dihedral angle of 84.86 (2)°. In the crystal structure, weak intermolecular C—H⋯O hydrogen bonds link molecules into extended chains propagating along the c axis.

In the title compound, C 10 H 5 Br 2 F 2 N 3 O, the mean planes of the benzene and triazole rings form a dihedral angle of 84.86 (2) . In the crystal structure, weak intermolecular C-HÁ Á ÁO hydrogen bonds link molecules into extended chains propagating along the c axis.
The molecular structure of the title compound is shown in Fig. 1. The mean planes of the benzene and triazole rings form a dihedral angle of 84.86 (2) °. In the crystal structure weak intermolecular C-H···O hydrogen bonds link molecules into extended chains along the c axis.

Experimental
To a solution of 1-(2,4-difluorophenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone (1.0 g, 4.4 mmol), sodium acetate (1.4 g, 4.4 mmol) and acetic acid (4 ml) was added the mixture of Br 2 (0.45 ml) and acetic acid (2.5 ml) dropwise, and stirred at 338-348 K. The progress of the reaction was monitored by TLC. Upon completion, the reaction was extracted with chloroform (15 ml × 3). The filtrate was concentrated and then directly purified by chromatographic column (chloroform) to afford the title compound (I). A crystal suitable for X-ray analysis was grown from a solution of (I) in a mixture of petroleum and chloroform by slow evaporation at room temperature.

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 > σ(F 2 ) is used only for calculating Rfactors(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.  (2)