3-(4-Bromophenyl)quinazolin-4(3H)-one

In the title compound, C14H9BrN2O, the quinazoline unit is essentially planar, with a mean deviation of 0.058 (2) Å from the least-squares plane defined by the ten constituent ring atoms. The dihedral angle between the mean plane of the quinazoline ring system and the 4-bromophenyl ring is 47.6 (1)°. In the crystal, molecules are linked by intermolecular C—H⋯N and C—H⋯O hydrogen bonds, forming infinite chains of alternating R 2 2(6) dimers and R 2 2(14) ring motifs.

In the title compound, C 14 H 9 BrN 2 O, the quinazoline unit is essentially planar, with a mean deviation of 0.058 (2) Å from the least-squares plane defined by the ten constituent ring atoms. The dihedral angle between the mean plane of the quinazoline ring system and the 4-bromophenyl ring is 47.6 (1) . In the crystal, molecules are linked by intermolecular C-HÁ Á ÁN and C-HÁ Á ÁO hydrogen bonds, forming infinite chains of alternating R 2 2 (6) dimers and R 2 2 (14) ring motifs.
In title molecule ( Fig. 1), the quinazoline unit is essentially planar, with a mean deviation of 0.058 (2) Å from the least square plane defined by the ten constituent atoms. The dihedral angle formed by the 4-bromophenyl ring and the mean plane of the quinazoline fragment is 47.6 (1)° . In the crystal packing, molecules are linked by intermolecular C-H···N and C-H···O hydrogen bonds (Table 1). These hydrogen bonds are forming infinite chains of alternating R 2 2 (6) dimer and R 2 2 (14) ring motifs (Bernstein et al., 1995) as shown in Fig. 2.

Experimental
To an ice-cold solution of 2.8 ml POCl 3 in 5 ml DMF was added anthranilic acid (2 g, 0.0146 mole) and stirred for 5-10 min until TLC indicated the disappearance of anthranilic acid. The reaction mixture was then treated with an equimolar amount of p-bromo-aniline (2.511 g) and supported on anhydrous sodium sulfate (five times the weight of anthranilic acid) and exposed to microwave (BPL company) irradiation (600 W) for 2-4 min with 30 sec pulse. The reaction mixture was quenched with water (50 ml) and extracted with ethyl acetate (2 x 50 ml). The organic layer was dried over anhydrous sodium sulfate, concentrated and purified by silica gel column chromatography (60-20 mesh) using hexane/EtOAc (7.5 : 2.5) as eluent to yield the pure product (yield: 4,397 g, 84%). Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in methanol at room temperature.

Refinement
Hydrogen atoms were placed in calculated positions with C-H = 0.93 Å and refined using a riding model with fixed a isotropic displacement parameter of U iso (H) = 1.2 U eq (C).

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.