Crystal structure of ethyl 2-(2,4,5-tri­meth­oxy­phen­yl)quinoline-4-carboxyl­ate

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

doi:10.1107/S2056989015011706

. 2015 Jun 27;71(Pt 7):o514–o515. doi: 10.1107/S2056989015011706

Crystal structure of ethyl 2-(2,4,5-trimethoxyphenyl)quinoline-4-carboxylate

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

PMCID: PMC4518944 PMID: 26279938

Abstract

In the title compound, C₂₁H₂₁NO₅, the dihedral angle between the quinoline ring system (r.m.s. deviation = 0.028 Å) and the trimethoxybenzene ring is 43.38 (5)°. The C atoms of the methoxy groups deviate from their attached benzene ring by −0.396 (2), −0.049 (2) and 0.192 (2) Å for the ortho-, meta- and para-substituents, respectively. The pendant ethyl chain is disordered over two orientations in a 0.527 (5):0.473 (5) ratio. A short intramolecular C—H⋯O contact closes an S(6) ring. In the crystal, inversion dimers linked by pairs of weak C—H⋯O interactions generate R ₂ ²(6) loops. The dimers are linked by further C—H⋯O interactions to generate [1-10] chains.

Keywords: crystal structure, quinoline, quinolone-4-ethyl carboxylate, hydrogen bonding, C—H⋯O interactions

Related literature

For background to quinolines and their properties, see: Beagley et al. (2003 ▸). For our work in this area, see: Pradeep et al. (2014 ▸); Shrungesh Kumar et al. (2015 ▸); Sunitha et al. (2015 ▸). graphic file with name e-71-0o514-scheme1.jpg

Experimental

Crystal data

C₂₁H₂₁NO₅
M _r = 367.39
Triclinic,
a = 8.3444 (3) Å
b = 9.3508 (4) Å
c = 12.2723 (5) Å
α = 104.079 (2)°
β = 97.282 (2)°
γ = 93.904 (2)°
V = 916.43 (6) Å³
Z = 2
Cu Kα radiation
μ = 0.78 mm⁻¹
T = 100 K
0.29 × 0.22 × 0.19 mm

Data collection

Bruker X8 Proteum diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2013 ▸) T _min = 0.797, T _max = 0.813
10087 measured reflections
3008 independent reflections
2601 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.117
S = 1.04
3008 reflections
277 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.28 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: Mercury.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015011706/hb7449sup1.cif

e-71-0o514-sup1.cif^{(30.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015011706/hb7449Isup2.hkl

e-71-0o514-Isup2.hkl^{(147.6KB, hkl)}

Click here for additional data file.^{(7.3KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015011706/hb7449Isup3.cml

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

. DOI: 10.1107/S2056989015011706/hb7449fig1.tif

A view of the title molecule, with displacement ellipsoids drawn at the 50% probability level.

CCDC reference: 1407284

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

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C14H14AO4	0.93	2.30	2.9073(18)	123
C9H9AO3ⁱ	0.96	2.53	3.397(2)	150
C20H20AO1ⁱⁱ	0.97	2.51	3.304(5)	139

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

Acknowledgments

The authors are thankful to the IOE, Vijnana Bhavana, University of Mysore, Mysore, for providing the single-crystal X-ray diffractometer facility.

supplementary crystallographic information

S1. Comment

Quinolines have been found to possess a wide spectrum of biological activities (Beagley et al., 2003,). Among them, the quinolone-4-ethyl carboxylates have been identified as potent antagonizing agents. Keeping 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, Shrungesh Kumar et al., 2015, Sunitha et al., 2015), the title compound was synthesized. The compound obtained was characterized spectroscopically and its structure was established by X-ray crystallographic studies.

In the title compound, C₂₁H₂₁O₅N, the carboxyl group is disordered. The two rings of the quinoline system are fused almost coaxially, with a dihedral angle between their planes of 2.66°. The dihedral angle between the quinoline ring system mean plane (r.m.s. deviation = 0.0238 Å) and the tri-methoxyphenyl ring is 43.34 (1)°. The structure exhibits both inter and intra-molecular hydrogen bonds of the type C–H···O.

S2. Experimental

¹H NMR was recorded at 400 MHz in CDCl₃ solvent. Mass spectra were recorded on a Jeol SX 102=DA-6000 (10 kV) fast atom bombardment (FAB) mass spectrometer.

A mixture of 2-(2,4,5-trimethoxyphenyl)quinoline-4-carboxylic acid 1.0 g (0.005 mol) and absolute EtOH (15 ml) was stirred at 0–5°C. A catalytic amount of concentrated H₂SO₄ was added drop wise into the flask until the powdered 2-(2,4,5-trimethoxyphenyl)quinoline-4-carboxylic acid was dissolved. The solution was then refluxed for 15–17 h. The completion of the reaction was monitored by TLC [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 obtain the crude product in 85% yield. The crude product was purified by column chromatography using silica gel (60–120 mesh, petroleum ether: ethyl acetate, 9:1 v/v). Colourless rectangular crystals grew after 4 days due to slow evaporation of the solvent. Yield = 85%. M·P. = 100–102 °C.