N,N-Dicyclo­hexyl-2-(5,7-dichloro-8-quinol­yloxy)acetamide

Jing-Lin Wang

doi:10.1107/S160053680903966X

. 2009 Oct 7;65(Pt 11):o2663. doi: 10.1107/S160053680903966X

N,N-Dicyclohexyl-2-(5,7-dichloro-8-quinolyloxy)acetamide

Jing-Lin Wang ^a,^*

PMCID: PMC2971332 PMID: 21578274

Abstract

The molecular and crystal structures of the title compound, C₂₃H₂₈Cl₂N₂O₂, are very close to those of the bromine-substituted analogue N,N-dicyclohexyl-2-(5,7-dibromo-8-quinolyloxy)acetamide. The two cyclohexyl groups adopt normal chair conformation. The amide N and C atoms have a planar configuration. The crystal packing is stabilized by intermolecular C—H⋯O hydrogen bonds and aromatic π⋯π stacking interactions [centroid–centroid separation = 3.5715 (4) Å for symmetry-related pyridine rings]. In addition, the crystal structure exhibits Cl⋯Cl halogen contacts of 3.4675 (3) Å.

Related literature

For background to the applications of 8-hydroxyquinoline and its derivatives, see: Bratzel et al. (1972 ▶); Hanna et al. (2002 ▶); Pierre et al. (2003 ▶); Tang et al. (1987 ▶); Zeng et al. (2006 ▶). For structures of 8-hydroxyquinolinate amide compounds, see: Bi et al. (2007 ▶); Tang et al. (2007 ▶); Liu et al. (2007 ▶).

Experimental

Crystal data

C₂₃H₂₈Cl₂N₂O₂
M _r = 435.37
Triclinic,
a = 9.8476 (11) Å
b = 10.7542 (12) Å
c = 11.1376 (12) Å
α = 72.392 (2)°
β = 86.880 (2)°
γ = 80.208 (2)°
V = 1107.9 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 293 K
0.22 × 0.20 × 0.18 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick,1996 ▶) T _min = 0.934, T _max = 0.946
5942 measured reflections
4088 independent reflections
3400 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.112
S = 1.02
4088 reflections
262 parameters
H-atom parameters constrained
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680903966X/bh2246sup1.cif

e-65-o2663-sup1.cif^{(21.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903966X/bh2246Isup2.hkl

e-65-o2663-Isup2.hkl^{(200.3KB, 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
C6—H6A⋯O2ⁱ	0.93	2.50	3.414 (3)	169
C10—H10B⋯O2ⁱⁱ	0.97	2.38	3.323 (2)	164

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

supplementary crystallographic information

Comment

8-Hydroxyquinoline and its derivatives have been used widely in analytical chemistry (Bratzel et al., 1972), coordination chemistry (Hanna et al., 2002), pharmaceutical chemistry (Pierre et al., 2003), materials chemistry (Tang et al., 1987) and many other topics. The synthesis and the development of novel 8-hydroxyquinoline derivatives have been a significant research subject (Zeng et al., 2006). Recently, the structures of 8-hydroxyquinolinate amide-type compounds, namely, N,N-diphenyl-2-(5,7-dibromoquinolin-8-yloxy)acetamide (Bi et al., 2007), N,N-diphenyl-2-(5,7-dichloroquinolin-8-yloxy)acetamide (Tang et al., 2007), and N,N-dicyclohexyl-2-(5,7-dibromoquinolin-8-yloxy)acetamide (Liu et al., 2007) have been reported. Here, we report the synthesis and crystal structure of the title compound, (I, Fig. 1), a new amide-based 5,7-dichloro-8-hydroxyquinoline derivative.

All bond lengths and angles in (I) are within normal ranges and comparable with those in the related above-cited compounds. Compound (I) has the same crystal form as the bromine analogue. The quinoline fragment is essentially planar, with a dihedral angle of 0.35 (9)° between the benzene (C1···C4/C8/C9) ring and pyridine (N1/C4···C8) ring. The two cyclohexyl groups adopt the normal chair conformation. The amide N and C atoms have a planar configuration. The crystal packing exhibits intermolecular C6—H6···O2 and C10—H10···O2 hydrogen bonds (Table 1 and Fig. 2), and π···π interactions [shortest centroid-centroid separation = 3.5715 (4) Å] between the pyridine rings of the neighbouring molecules. In addition, the crystal structure exhibits Cl···Cl halogen contacts of 3.4675 (3) Å.

Experimental

To a solution of 5,7-dichloro-8-hydroxyquinoline (4.18 g, 20 mmol) in acetone (60 ml) were added 2-chloro-N,N-dicyclohexylacetamide (5.16 g, 20 mmol), K₂CO₃ (3.04 g, 22 mmol) and KI (0.5 g), and the resulting mixture was refluxed for 5 h. After cooling to room temperature, the mixture was washed three times with water and filtered. The filter cake was collected and purified by recrystallization with a mixture of ethanol/water. Colourless single crystals of (I) suitable for X-ray diffraction study were obtained by slow evaporation of an ethanol solution over a period of 15 d.