4-Chloro-6,7-dimeth­oxy­quinoline

Min Wu

doi:10.1107/S1600536811042589

. 2011 Oct 22;67(Pt 11):o3012. doi: 10.1107/S1600536811042589

4-Chloro-6,7-dimethoxyquinoline

Min Wu ^a,^*

PMCID: PMC3247411 PMID: 22220029

Abstract

The title molecule, C₁₁H₁₀ClNO₂, is almost planar with the C atoms of the methoxy groups deviating by −0.082 (2) and 0.020 (2) Å from the least-squares plane defined by the atoms of the quinoline ring system (r.m.s. deviation = 0.002 Å). An intramolecular C—H⋯Cl interaction generates an S(5) ring motif.

Related literature

For related structures, see: Davies & Bond (2001 ▶); Yathirajan et al. (2007 ▶). For biological properties of quinoline derivatives, see: Franck et al. (2004 ▶); Moret et al. (2006 ▶); Furuta et al. (2006 ▶); Ilovich et al. (2008 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₁H₁₀ClNO₂
M _r = 223.65
Monoclinic,
a = 12.5530 (17) Å
b = 4.6499 (7) Å
c = 18.274 (3) Å
β = 105.786 (2)°
V = 1026.4 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.35 mm⁻¹
T = 296 K
0.3 × 0.2 × 0.2 mm

Data collection

Rigaku SCXmini diffractometer
6840 measured reflections
1808 independent reflections
1542 reflections with I > 2σ(I)
R _int = 0.034
3 standard reflections every 150 reflections intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.115
S = 1.08
1808 reflections
139 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811042589/lr2029sup1.cif

e-67-o3012-sup1.cif^{(14.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811042589/lr2029Isup3.hkl

e-67-o3012-Isup3.hkl^{(89KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811042589/lr2029Isup3.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
C8—H8⋯Cl1	0.93	2.70	3.0827 (17)	105

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Acknowledgments

We gratefully acknowledge financial support by the Natural Science Foundation of Jiangsu Province (BK2009293) and the Educational Commission of Jiangsu Province (JHB 2011–2).

supplementary crystallographic information

Comment

Quinoline derivatives have been interesting to researchers for many years because a large number of natural products contain these heterocycles and also because their varied biological activities ( Franck et al. 2004; Moret et al. 2006; Furuta et al. 2006 & Ilovich et al. 2008).

Prompted by the properties of quinoline derivatives, the title compound, C₁₁H₁₀ClNO₂, has been synthesized. Bond lengths and angles are in the usual range (Davies & Bond 2001 & Yathirajan et al. 2007) and the whole molecule is almost planar with the carbon atoms of the methoxyl groups deviating 0.08 (C10) and 0.02Å (C11) from the least-square plane defined by the atoms of the quinoline ring. There are intramolecular C8 — H8 ···Cl1 interactions (Table 1) generating S(5) ring motifs (Bernstein et al. 1995) . Figure 1 shows the molecular structure of the title compound and Figure 2 is a partial paking view of the crystal structure down the b axis.

Experimental

A mixture of 6,7- dimethoxynaphthalen-1-ol (20.4 g, 100 mmol) and POCl₃ (60 ml, 640 mmol) was heated under reflux for 6 h. The excess of phosporus oxychoride was distilled out under reduced pressure. 200 g crush ice was added to the residue followed by 50% aqueous NaOH until the pH was adjusted to 8. The resulting solid was collected by filtration and washed with water to give the crude product. Purification of the crude product by a column chromatography (petroleum ether: EtOAc = 8:1 v.v) afforded the title compound (15.6 g, 70%) as pink crystals.The purity of the product, 4- chloro- 6, 7- dimethoxy- quinoline, was determined using a reversed- phase C-18 analytical HPLC column (99% purity). Crystals of the title compound suitable for X– ray diffraction were obtained by slow evaporation of methanol solution at room temperature. m. p. 403- 404 K; ¹H NMR (DMSO– d₆): δ8.57 (d, J = 5.1 Hz, 1H), 7.40 (d, J = 4.8 Hz, 1H), 7.37 (s, 1H), 7.32 (s, 1H), 4.04 (s, 3H), 4.03 (s. 3H). MS (ESI, m/z): 224 (M+1).