Crystal structure of ethyl 6-bromo-2-[(E)-2-phenyl­ethen­yl]quinoline-4-carboxyl­ate

T O Shrungesh Kumar; S Naveen; M N Kumara; K M Mahadevan; N K Lokanath

doi:10.1107/S2056989014028266

. 2015 Jan 17;71(Pt 2):o121. doi: 10.1107/S2056989014028266

Crystal structure of ethyl 6-bromo-2-[(E)-2-phenylethenyl]quinoline-4-carboxylate

T O Shrungesh Kumar ^a, S Naveen ^b, M N Kumara ^c, K M Mahadevan ^d, N K Lokanath ^e,^*

PMCID: PMC4384604 PMID: 25878862

Abstract

In the title compound, C₂₀H₁₆BrNO₂, the dihedral angle between the quinolone ring system mean plane (r.m.s. deviation = 0.018 Å) and the phenyl ring bridged by the ethynyl group, is 25.44 (14)°. There is an intramolecular C—H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, molecules are linked via C—H⋯O hydrogen bonds forming chains propagating along the b-axis direction.

Keywords: crystal structure, quinoline, quinoline-4-carboxylate, hydrogen bonding

Related literature

For pharmaceutical and pharmacological activities of quinolines, see: Beagley et al. (2003 ▸). The title compound was synthesized in a continuation of our work on new quinoline-based therapeutic agents, see: Pradeep et al. (2014 ▸). graphic file with name e-71-0o121-scheme1.jpg

Experimental

Crystal data

C₂₀H₁₆BrNO₂
M _r = 382.24
Orthorhombic,
a = 14.0819 (7) Å
b = 9.7470 (5) Å
c = 24.0399 (12) Å
V = 3299.6 (3) Å³
Z = 8
Cu Kα radiation
μ = 3.49 mm⁻¹
T = 293 K
0.30 × 0.27 × 0.25 mm

Data collection

Bruker X8 Proteum diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2013 ▸) T _min = 0.421, T _max = 0.476
12970 measured reflections
2722 independent reflections
2213 reflections with I > 2σ(I)
R _int = 0.071

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.134
S = 1.04
2722 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 0.78 e Å⁻³
Δρ_min = −0.92 e Å⁻³

Data collection: APEX2 (Bruker, 2013 ▸); cell refinement: SAINT (Bruker, 2013 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: Mercury (Macrae et al., 2008 ▸); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989014028266/su5042sup1.cif

e-71-0o121-sup1.cif^{(25.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989014028266/su5042Isup2.hkl

e-71-0o121-Isup2.hkl^{(133.7KB, hkl)}

Click here for additional data file.^{(6.2KB, cml)}

Supporting information file. DOI: 10.1107/S2056989014028266/su5042Isup3.cml

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S2056989014028266/su5042fig1.tif

A view of molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The intramolecular hydrogen bond is shown as dashed line (see Table 1 for details).

Click here for additional data file.^{(1.2MB, tif)}

a . DOI: 10.1107/S2056989014028266/su5042fig2.tif

A partial view along the a axis of the crystal packing of the title compound. The intra- and inter-molecular hydrogen bonds are shown as dashed lines (see Table 1 for details; H atoms: grey balls; H atoms not involved in hydrogen bonding have been omitted for clarity).

CCDC reference: 1041593

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C6H6O13	0.93	2.22	2.848(4)	124
C15H15AO13ⁱ	0.97	2.51	3.413(4)	154

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are grateful to the Institution of Excellence, Vijnana Bhavana, University of Mysore, Mysuru, for providing the single-crystal X-ray diffractometer facility.

supplementary crystallographic information

S1. Comment

Quinolines have been considered as the most prevalent N-hetero aromatic compounds that exhibit a wide spectrum of pharmaceutical and pharmacological activities (Beagley et al., 2003). Some of the quinoline-4-carboxylates were reported to possess potent 5HT₃ antagonizing activity and anti-emetic activity. In view of their broad spectrum of medicinal properties and in continuation of our work on new quinoline based therapeutic agents (Pradeep et al., 2014), the title compound was synthesized, and we report herein on its crystal structure.

The molecular structure of the title molecule is shown in Fig. 1. The quinoline ring system (N1/C2-C10) is planar with the maximum deviations from the mean plane being for atoms C8 and C5 viz. 0.018 (2) Å. The dihedral angle between the quinoline ring and the phenyl ring (C19–C24) bridged by the ethynyl group is 25.44 (14)°. The two rings of the quinolyl moiety are fused in an axial fashion and form a dihedral angle of 1.15 (13)°.

In the crystal, molecules are linked via C–H···O hydrogen bonds forming chains propagating along the b axis direction (Table 1 and Fig. 2).

S2. Experimental

A mixture of 2-aryl-6-chloro/bromo quinoline-4-carboxylic acid (1.0 g) and absolute EtOH (15 ml) was stirred at 273 - 278 K. The concentrated sulfuric acid (2 - 3 ml) was added drop wise into the flask until the powdered 2-aryl-6-chloroquinoline-4-carboxylic acid was completely dissolved. The solution was then refluxed for 15–17 h. The completion of the reaction was monitored by thin layer chromatography [hexane and ethyl acetate (9:1 v/v)]. The reaction mixture was poured into a crushed ice (100 ml), the precipitate was collected by filtration, washed with water and EtOH, dried under vacuum to afford crude product. The crude product was purified by column chromatography using silica gel (60–120 mesh, petroleum ether: ethyl acetate, 9:1 v/v). Green block-shaped crystals were obtained by slow evaporation of the solvent.

¹H-NMR(400 MHz, CDCl₃): δ = 8.95 (d, J = 2.00 Hz, 1H), 8.17 (s, 1H), 7.99 (d, J = 4.40 Hz, 1H), 7.82 (d, J = 2.40 Hz, 1H), 7.81 (t, J = 2.00 Hz, 1H), 7.75 (s, 1H), 7.65 (d, J = 7.20 Hz, 1H), 7.35–7.35 (m, 4H), 4.54 (q, J = 7.20 Hz, 2H), 1.46–1.49 (m, 3H) p.p.m.. MS (70 eV) m/z (%): 382.0 (M⁺).