1-(6,8-Dibromo-2-methyl­quinolin-3-yl)ethanone

R Prasath; P Bhavana; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536811037044

. 2011 Sep 17;67(Pt 10):o2664. doi: 10.1107/S1600536811037044

1-(6,8-Dibromo-2-methylquinolin-3-yl)ethanone

R Prasath ^a, P Bhavana ^a,^‡, Seik Weng Ng ^b,^c, Edward R T Tiekink ^b,^*

PMCID: PMC3201233 PMID: 22058780

Abstract

Two independent molecules,1 and 2, with similar conformations comprise the asymmetric unit in the title compound, C₁₂H₉Br₂NO. The major difference between the molecules relates to the relative orientation of the ketone–methyl groups [the C—C—C—C torsion angles are −1.7 (6) and −16.8 (6)° for molecules 1 and 2, respectively]; in each case, the ketone O atom is directed towards the ring-bound methyl group. The crystal packing comprises layers of molecules, sustained by C—H⋯O and π–π {ring centroid(C₆) of molecule 2 with NC₅ of molecule 1 [3.584 (3) Å] and NC₅ of molecule 2 [3.615 (3) Å]} interactions. C—H⋯Br contacts also occur.

Related literature

For background details and the biological applications of quinolines, see: Kalluraya & Sreenivasa (1998 ▶); Xiang et al. (2006 ▶). For a related structure, see: Prasath et al. (2011 ▶). For additional structure analysis, see: Spek (2009 ▶).

Experimental

Crystal data

C₁₂H₉Br₂NO
M _r = 343.02
Triclinic,
a = 9.7549 (5) Å
b = 11.1719 (6) Å
c = 11.5629 (5) Å
α = 99.043 (4)°
β = 93.330 (4)°
γ = 111.733 (5)°
V = 1146.69 (10) Å³
Z = 4
Cu Kα radiation
μ = 8.78 mm⁻¹
T = 100 K
0.25 × 0.20 × 0.15 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.218, T _max = 0.353
6906 measured reflections
4462 independent reflections
4281 reflections with I > 2σ(I)
R _int = 0.039

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.139
S = 1.11
4462 reflections
293 parameters
H-atom parameters constrained
Δρ_max = 1.60 e Å⁻³
Δρ_min = −1.38 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶), DIAMOND (Brandenburg, 2006 ▶) and Qmol (Gans & Shalloway, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811037044/hb6406sup1.cif

e-67-o2664-sup1.cif^{(21.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811037044/hb6406Isup2.hkl

e-67-o2664-Isup2.hkl^{(218.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811037044/hb6406Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯O2ⁱ	0.95	2.56	3.453 (7)	157
C15—H15⋯Br4ⁱⁱ	0.95	2.89	3.796 (5)	160
C19—H19⋯O1ⁱⁱⁱ	0.95	2.60	3.462 (6)	152

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

PB acknowledges the Department of Science and Technology (DST), India, for a research grant (SR/FTP/CS-57/2007). The authors also thank the University of Malaya for support of the crystallographic facility.

supplementary crystallographic information

Comment

Quinoline derivatives continue to attract wide interest owing to their occurrence in natural products and for their biological activity (Kalluraya & Sreenivasa, 1998; Xiang et al., 2006). In continuation of structural research in this area (Prasath et al., 2011), the title compound, (I), was investigated.

Two independent molecules comprise the crystallographic asymmetric of (I), Fig. 1. The molecules are virtually super-imposable as seen in Fig. 2. The r.m.s. deviations for the bond distances and angles are 0.0088 Å and 0.507 °, respectively (Spek, 2009). The major differences between the molecules are manifested in the values of the C7—C8—C11—C12 and C19—C20—C23—C24 torsion angles of -1.7 (6) and -16.8 (6) °, respectively indicating a twist of the ketone residue out of the plane of the quinolinyl ring in the second independent molecule. In each case, the ketone-O atom is directed towards the ring-methyl group.

In the crystal packing, C—H···O, Table 1, and π–π interactions are noted. The C—H···O and two closest π–π interactions lead to the formation of layers in the ac plane. The π–π interactions occur between the (C13–C18) ring and each of the (N1,C1,C6–C9)ⁱ [3.584 (3) Å] and (N2,C13,C18–C21)ⁱⁱ [3.615 (3) Å] rings; symmetry operation i: 1 - x, 1 - y, 1 - z and ii: 1 - x, 1 - y, 2 - z. The resultant layers stack along the b axis, Fig. 3.

Experimental

To a mixture of 2-amino-3,5-dibromobenzaldehyde (0.01 M, 2.70 g) and acetylacetone (0.01 M, 1.02 ml), 10 ml of 1 N HCl was added. The reaction mixture was stirred at 363 K for 3 h. At the end of this period, the resulting suspension was neutralized with 10 ml of 1 N NaOH. The resultant solid was filtered, dried and purified by column chromatography using a 1:1 mixture of chloroform and hexane. Recrystallization was by slow evaporation of a chloroform solution of (I) which yielded light-brown prisms. Yield: 90%. M.pt. 433–435 K.