Crystal structure of 3-bromomethyl-2-chloro-6-(dibromomethyl)quinoline

In the title compound, C11H7Br3ClN, the quinoline ring system is approximately planar (r.m.s. = 0.011 Å). In the crystal, molecules are linked by C—H⋯Br interactions forming chains along [10-1]. The chains are linked by C—H⋯π and π–π interactions involving inversion-related pyridine rings [intercentroid distance = 3.608 (4) Å], forming sheets parallel to (10-1). Within the sheets, there are two significant short interactions involving a Br⋯Cl contact of 3.4904 (18) Å and a Br⋯N contact of 3.187 (6) Å, both of which are significantly shorter than the sum of their van der Waals radii.


Related literature
The title compound is an important intermediate in the manufacture of materials such as organic light-emitting devices. For the synthesis of the title compound, see: Jones (1977); Lyle et al. (1972). For the biological activity of quinoline derivatives, see: Chauhan & Srivastava (2001); Ferrarini et al. (2000); Chen et al. (2001); Sahin et al. (2008 Table 1 Hydrogen-bond geometry (Å , ).
Cg2 is the centroid of the C4-C9 ring.

S1. Synthesis and crystallization
The title compound was prepared in line with literature methods (Jones, 1977;Lyle et al., 1972). 2-Chloro-3,6-dimethylquinoline (0.001 mole) was dissolved in CCl 4 . To this benzoyl peroxide (50 mg) was added and the mixture was stirred under ice-cold conditions. To this mixture N-bromosuccinimide (0.005 mole) was added portion wise. The whole mixture was further stirred under ice-cold condition for 1 h. The reaction mixture was then refluxed for about 10 hours. After completion of the reaction, the succinimide was removed (it was insoluble in CCl 4 ) by filtration and washed with 20 ml of CCl 4 . The contents of the filtrate were reduced to half, and the residue was chromatographed on silica gel using petroleum ether and ethyl acetate as eluent (99:1), which gave the titled product (yield: 52%). The white solid obtained was then recrystallized using acetone yielding colourless block-like crystals.

S2. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. H atoms were included in calculated positions and refined using a riding model: C-H = 0.95 -1.0 Å with U iso (H) = 1.2U eq (C). The highest peak in the final difference Fourier map (1.654 eÅ -3 ) is close to atom Cl1. Attempts to split this atom were unsuccessful.

S3. Structural commentary
The presence of the quinoline skeleton in the frameworks of pharmacologically active compounds and natural products has spurred on the development of different strategies for their synthesis (Chauhan et al., 2001;Ferrarini et al., 2000;Chen et al., 2001). Bromoquinolines have been of interest for chemists as precursors for heterocyclic compounds with multifunctionality, giving accessibility to a wide variety of compounds. These building blocks have been used in medicinal chemistry as starting materials for numerous compounds with pharmacological activity (Sahin et al., 2008).
The molecular structure of the title compound is shown in Fig. 1. The quinoline ring is planar (r.m.s. = 0.011 Å).
In the crystal, molecules are linked by C-H···Br interactions forming chains along [101]; Table 1 and Fig. 2. The chains are linked by C-H···π (Table 1), and π-π interactions involving inversion related pyridine rings (N1/C1-C5) with an inter-centroid distance of 3.608 (4)   The molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
A view along the a axis of the crystal packing of the title compound. The C-H···Br hydrogen bonds, C-H···π  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 1.65 e Å −3 Δρ min = −1.19 e Å −3 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.