1-Bromo-4-methyl-2-nitrobenzene

In the title compound, C7H6BrNO2, the dihedral angle between the nitro group and the phenyl ring is 14.9 (11)°.

In the title compound, C 7 H 6 BrNO 2 , the dihedral angle between the nitro group and the phenyl ring is 14.9 (11) .

Comment
The title compound is a synthetic intermediate in the synthesis of 4-methoxymethylbenzyl alcohol containing bromine, which is an alcohol moiety having insecticidal activity of pyrethroids (Zou et al., 2002). It is a pale yellow liquid, but needle-like crystals were obtained by a slow cooling process from room temperature to 0 °C and the crystal structure was determined at 181 K (Fig. 1).
The dihedral angle between the plane of the nitro group and the best plane through the phenyl ring is 14.9 (11)°. In nitrobenzene structures, the dihedral angle between the nitro group and the phenyl ring is sensitive to its chemial environment, especially the ortho group. In the crystal structure of 4-methyl-2-nitroaniline (Ellena et al.,1996), the nitro group having an amino group as neighbour is almost coplanar with the phenyl ring [dihedral angle 3.2 (3)°]. With larger methyl groups as neighbour in pentamethylnitrobenzene (Gatilov et al.,1975) the dihedral angle is 86.1 (5)°. In the crystal structure of the analogous compound 2-bromo-3-nitrotoluene (Fricke et al.,2002), the dihedral angle between the nitro group and the phenyl ring is 54.1 (4)°.
There are no obvious interactions between neighbouring molecules in the packing.

Experimental
The title compound was synthesised as described by Moodie et al. (1976). The obtained compound is a pale yellow liquid at room temperature. The needle-like crystal was obtained by slowly cooling from room temperature to 0 °C.

Refinement
All H atoms were geometrically fixed and allowed to ride on their attached atoms, with C-H = 0.93Å for the phenyl group and U iso (H)= 1.2U eq (C) and C-H = 0.96Å for the methyl group and U iso (H)= 1.5U eq (C). The U ij components of O1 and O2 have been restrained to isotropic behavior and those of the N-O bonds to have the same U ij components. Fig. 1. The molecular structure of the title compound with displacement ellipsoids 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 supplementary materials sup-3 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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )