4-Bromo-N-phenylbenzamide

The molecule of the title benzamide derivative, C13H10BrNO, is twisted with the dihedral angle between the phenyl and 4-bromophenyl rings being 58.63 (9)°. The central N—C=O plane makes dihedral angles of 30.2 (2) and 29.2 (2)° with the phenyl and 4-bromophenyl rings, respectively. In the crystal, molecules are linked by N—H⋯O hydrogen bonds into chains along [100]. C—H⋯π contacts combine with the N—H⋯O hydrogen bonds, to form a three-dimensional network.

The molecule of the title benzamide derivative, C 13 H 10 BrNO, is twisted with the dihedral angle between the phenyl and 4bromophenyl rings being 58.63 (9) . The central N-C O plane makes dihedral angles of 30.2 (2) and 29.2 (2) with the phenyl and 4-bromophenyl rings, respectively. In the crystal, molecules are linked by N-HÁ Á ÁO hydrogen bonds into chains along [100]. C-HÁ Á Á contacts combine with the N-HÁ Á ÁO hydrogen bonds, to form a three-dimensional network.

Boonnak Comment
Benzamides are recognised as one of the bioactive skeletons, and some benzamide derivatives exhibit various potent pharmaceutical activities (Brown et al., 1991;Hu et al., 2008). They have been developed as anti-tumor (Olsson et al., 2002), antibacterial (Mobinikhaledi et al., 2006) and anti-Alzheimer's agents (Xu et al., 2009). Cisapride (CIS) is an effective benzamide derived drug which can act as a gastrointestinal prokinetic agent. It also has restricted usage for the treatment of gastroesophageal reflux disease in some countries (World Health Organization, 2003) due to its cardiac side effects. The formulation of a more stable CIS oral suspension was studied (Boonleang & Tanthana, 2010). We have synthesized several N-phenylbenzamide derivatives in order to evaluate their antibacterial and anti-Alzheimer's activities, and the structure of the title benzamide derivative (I) is reported here.
In the crystal packing ( Fig. 2), the molecules are linked by N-H···O hydrogen bonds (Table 1) into chains along the [100] direction. C-H···π contacts involving H atoms from both the phenyl and 4-bromophenyl rings combine with the N -H···O hydrogen bonds to form a 3-dimensional network (Table 1).

Experimental
To the solution of 4-bromobenzoyl chloride (0.20 g, 0.91 mmol) in acetone (10 ml), aniline (0.12 ml, 1.37 mmol) was added and refluxed for 6 h. After the reaction was completed, a gray solid mass formed which was filtered and washed with distilled water. Colorless needle-shaped single crystals of the title compound suitable for X-ray structure determination were recrystallized from acetone/CH 3 OH (1:1 v/v) by slow evaporation of the solvent at room temperature over a week, Mp. 474-475 K.

Refinement
The amide H atom was located in a difference map and refined isotropically. The aromatic H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(C-H) = 0.95 Å and the U iso values were constrained to be 1.2U eq of the carrier atom.

Figure 1
The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.

Figure 2
The crystal packing of the title compound viewed along the b axis, showing the molecular chains along the [100] direction. N-H···O hydrogen bonds were drawn as dashed lines.  (Cosier & Glazer, 1986) operating at 120.0 (1) K. 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.