2,4-Dichloro­quinoline

Roman Kimmel; Marek Nečas; Robert Vícha

doi:10.1107/S160053681001576X

. 2010 May 8;66(Pt 6):o1261. doi: 10.1107/S160053681001576X

2,4-Dichloroquinoline

Roman Kimmel ^a, Marek Nečas ^b, Robert Vícha ^a,^*

PMCID: PMC2979494 PMID: 21579364

Abstract

The asymmetric unit of the title compound, C₉H₅Cl₂N, consists of two crystallographically independent molecules. In both molecules the quinoline ring system is essentially planar [maximum deviations from the best plane of 0.0232 (13) 0.0089 (15) Å]. The angle between these planes is 22.40 (3)°. Conformers A and B are arranged face-to-face along the c axis, forming alternating pairs in the order AABB. The interplanar distances AA, AB and BB are 3.3166 (11), 3.2771 (11) and 3.3935 (11) Å, respectively. The crystal packing is stabilized by weak C—H⋯Cl and C—H⋯N interactions.

Related literature

For previous syntheses of title compound, see: Baeyer & Bloem (1882 ▶); Steinschifter & Stadlbauer (1994 ▶). For the use of the title compound in organic synthesis, see: Buchmann & Hamilton (1942 ▶).

Experimental

Crystal data

C₉H₅Cl₂N
M _r = 198.04
Monoclinic,
a = 10.3689 (3) Å
b = 11.9215 (3) Å
c = 13.6380 (5) Å
β = 98.937 (3)°
V = 1665.37 (9) Å³
Z = 8
Mo Kα radiation
μ = 0.71 mm⁻¹
T = 120 K
0.40 × 0.40 × 0.30 mm

Data collection

Kuma KM-4-CCD diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006 ▶) T _min = 0.60, T _max = 0.81
13224 measured reflections
2927 independent reflections
2504 reflections with I > 2σ(I)
R _int = 0.012

Refinement

R[F ² > 2σ(F ²)] = 0.021
wR(F ²) = 0.066
S = 1.08
2927 reflections
217 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2006 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681001576X/bg2343sup1.cif

e-66-o1261-sup1.cif^{(16.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681001576X/bg2343Isup2.hkl

e-66-o1261-Isup2.hkl^{(143.7KB, hkl)}

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
C2—H2A⋯Cl4	0.95	2.88	3.7197 (14)	148
C17—H17A⋯N1ⁱ	0.95	2.60	3.5111 (19)	162
C18—H18A⋯Cl1ⁱ	0.95	2.95	3.7290 (15)	141

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Symmetry code: (i) Inline graphic .

Acknowledgments

The financial support of this work by the Czech Ministry of Education, project No. MSM 7088352101, and the Tomas Bata Foundation is gratefully acknowledged.

supplementary crystallographic information

Comment

Although the 2,4-dichloroquinoline is well known for more than hundred years (Baeyer & Bloem, 1882) and has been widely used in quinoline chemistry (Buchmann & Hamilton, 1942; Steinschifter & Stadlbauer, 1994), no structure data has been published so far.

The title compound (Fig. 1) crystallises with two crystallographical independent molecules in asymmetric unit. Conformers A and B differ very little in geometrical parameters. Both of them consist of essentially planar quinoline ring with maximum deviations from the best planes being 0.0232 (13) Å for atom C2 (conformer A) and 0.0089 (15) Å for atom C17 (conformer B). The angle between these quinoline best planes is 22.40 (3)°. Chlorine atoms lay almost in the ring best planes with the deviations 0.0035 (4) Å for atom Cl1 and -0.0011 (4) for atom Cl2 (conformer A) and -0.0081 (4) Å for atom Cl3 and 0.0121 (4) Å for atom Cl4 (conformer B). Pairs of conformers are stacked along the c axes in AABB arrangement stabilised via offset π–π interactions. The distances between AA, AB and BB planes calculated as a distance of nitrogen atom from adjacent ring plane are 3.3166 (11), 3.2771 (11) and 3.3935 (11) Å, respectively. Molecular packing is stabilised by C—H···Cl and C—H···N weak interactions (Fig. 2, Table 1).

Experimental

4-Hydroxyquinolin-2-one (322 mg, 2 mmol) and POCl₃ (2 ml) were treated for 15 min. at 100°C. Reaction mixture was poured onto finely crushed ice to decompose an excess of POCl₃. Basicity was adjusted to pH =8 using Na₂CO₃ and resulting precipitate was filtered off. The solid on the filter was washed with water and dried at room temperature to yield 292 mg (74%) of title compound.The single crystal used for data collection was obtained by crystallisation from diethyl ether at room temperature.