Ethyl 4-(5-bromo-2-hy­droxy­phen­yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxyl­ate

Malahat M Kurbanova; Elnur Z Huseynov; Atash V Gurbanov; Abel M Maharramov; Reza Kia

doi:10.1107/S1600536813006739

. 2013 Mar 16;69(Pt 4):o541. doi: 10.1107/S1600536813006739

Ethyl 4-(5-bromo-2-hydroxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

Malahat M Kurbanova ^a, Elnur Z Huseynov ^a, Atash V Gurbanov ^a,^*, Abel M Maharramov ^a, Reza Kia ^b,^c

PMCID: PMC3629593 PMID: 23634080

Abstract

In the title compound, C₂₁H₂₄BrNO₄, the dihedral angle between the heterocyclic ring and the pendant aromatic ring is 80.20 (13)°. The hexahydroquinone [i.e. the one with the C=O group] ring adopts a sofa conformation. An intramolecular O—H⋯O hydrogen bond generates an S(6) ring motif. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 (10). In the crystal, molecules are linked by N—H⋯O interactions, forming chains parallel to [101]. There are no significant C—H⋯π or π–π interactions in the crystal structure.

Related literature

For standard bond lengths, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For background to hexahydroquinoline compounds and their applications, see: Sausins & Duburs (1988 ▶); Nakayama & Kasoaka (1996 ▶); Klusa (1995 ▶). For the synthesis of related compounds, see: Kumar et al. (2008 ▶); Song et al. (2012 ▶).

Experimental

Crystal data

C₂₁H₂₄BrNO₄
M _r = 434.32
Monoclinic,
a = 9.5969 (3) Å
b = 19.0805 (5) Å
c = 11.0678 (3) Å
β = 97.387 (1)°
V = 2009.84 (10) Å³
Z = 4
Mo Kα radiation
μ = 2.07 mm⁻¹
T = 294 K
0.24 × 0.22 × 0.18 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.636, T _max = 0.707
23241 measured reflections
5008 independent reflections
3604 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.136
S = 1.05
5008 reflections
266 parameters
3 restraints
H-atom parameters constrained
Δρ_max = 1.10 e Å⁻³
Δρ_min = −1.02 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Click here for additional data file.^{(29.5KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813006739/rz5051sup1.cif

e-69-0o541-sup1.cif^{(29.5KB, cif)}

Click here for additional data file.^{(245.3KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813006739/rz5051Isup2.hkl

e-69-0o541-Isup2.hkl^{(245.3KB, hkl)}

Click here for additional data file.^{(7.6KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813006739/rz5051Isup3.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
O4—H4⋯O1	0.88	1.75	2.625 (3)	171
N1—H1⋯O2ⁱ	0.86	2.05	2.866 (3)	158

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Chemistry Department, Baku State University, for providing the X-ray diffraction facility.

supplementary crystallographic information

Comment

Hexahydroquinoline derivatives possess a variety of biological activities, such as vasodilatory, bronchodilatory, antiatherosclerotic, hepatoprotective, and antidiabetic activity (Sausins et al., 1988), and some of them have been used as calcium channel modulators and curatives for cardiovascular diseases (Nakayama et al., 1996). In past years, their uses as neuroprotectants, platelet anti-aggregatory agents, and cerebral anti-ischemic agents in the treatment of Alzheimer's disease and as chemosensitizers in tumor therapy have been also reported (Klusa, 1995).

The asymmetric unit of the title compound, Fig. 1, comprises a substituted hexahydroquinoline compound. Both six-membered rings of the hexahydroquinoline ring system adopt a half-boat conformation. Bond lengths (Allen et al., 1987) and angles are within normal ranges. An intramolecular O—H···O hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995). In the crystal structure, molecules are linked together by intermolecular N—H···O hydrogen interactions (Table 1, Fig. 2) forming chains parallel to the [101] direction. The ethyl group is disordered over two sets of sites with a refined site occupancy ratio of 0.633 (10):0.366 (10). The compound contains one chiral center but the space group is centrosymmetric, so the molecule exists as a racemate.

Experimental

5-Bromsalicylaldehyde (0.201 g, 1 mmol), ethyl acetoacetate (0.25 ml, 1 mmol), dimedone (0.14 g, 1 mmol), ammonium acetate (0.116 g, 1.5 mmol) and ethanol (15 ml) were charged in a round bottom flask. Then the reaction mixture was stirred at room temperature for 12 hours, then the product was separated by filtration. Recrystallization was effected by using ethanol as solvent. Yield 86%. M. p. 520 K.