Ethyl 3-(3-oxo-3,4-dihydro­quinoxalin-2-yl)propano­ate

Waqar Nasir; Munawar Ali Munawar; Ahmad Adnan; Saeed Ahmad; Mohammad Akbar

doi:10.1107/S1600536810047094

. 2010 Nov 20;66(Pt 12):o3224. doi: 10.1107/S1600536810047094

Ethyl 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoate

Waqar Nasir ^a, Munawar Ali Munawar ^a,^*, Ahmad Adnan ^b, Saeed Ahmad ^c, Mohammad Akbar ^b

PMCID: PMC3011385 PMID: 21589514

Abstract

In the title compound, C₁₃H₁₄N₂O₃, the fused ring system is almost planar (r.m.s. deviation = 0.015 Å). The r.m.s. deviation for all the non-H atoms of the molecule is 0.065Å. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds generate polymeric chains along the b axis containing alternating centrsymmetric R ₂ ²(8) and R ₂ ²(20) loops.

Related literature

For the synthesis, see: Taylor et al. (1965 ▶). For the biological activity of benzopyrazines, see: Sona et al. (1998 ▶); Cai et al. (1997 ▶); Toshima et al. (2003 ▶); Benbow et al. (2007 ▶); Sarges et al. (1990 ▶); Smits et al. (2008 ▶); Tandon et al. (2006 ▶).

Experimental

Crystal data

C₁₃H₁₄N₂O₃
M _r = 246.26
Monoclinic,
a = 8.3138 (6) Å
b = 13.6868 (8) Å
c = 10.8189 (8) Å
β = 102.002 (3)°
V = 1204.16 (14) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.37 × 0.29 × 0.23 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.965, T _max = 0.978
11123 measured reflections
2938 independent reflections
1370 reflections with I > 2σ(I)
R _int = 0.060

Refinement

R[F ² > 2σ(F ²)] = 0.068
wR(F ²) = 0.216
S = 0.96
2938 reflections
167 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810047094/hb5740sup1.cif

e-66-o3224-sup1.cif^{(17.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810047094/hb5740Isup2.hkl

e-66-o3224-Isup2.hkl^{(141.3KB, 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
N1—H1N⋯O1ⁱ	0.96 (6)	1.87 (6)	2.827 (3)	179 (5)
C3—H3⋯O3ⁱⁱ	0.93	2.51	3.426 (4)	170

Open in a new tab

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

Acknowledgments

The authors are grateful to the HEC (Higher Education Commission of Pakistan) for the financial support of this work.

supplementary crystallographic information

Comment

Benzopyrazine constitute an important class of nitrogen containing heterocyclic compounds. Literature has shown that these compounds possess a vide variety of applications from pharmaceutical to agricultural fields. Several benzopyrazines have been reported as anti-bacterial (Sona et al., 1998), anti-convulsant(Cai et al., 1997), anti-cancer (Toshima et al., 2003), antidiabetic(Benbow et al., 2007), antidepressant(Sarges et al., 1990), antifungal(Tandon et al., 2006), anti-inflammatory (Smits et al., 2008), etc. The present work is based on the synthesis of pyrazines derivatives which may possess enhanced pharmaceutical activities.

The title compound (I) is structurally looks like planer but the dihedral angle between the two fused rings i.e. aromatic ring (C1/C2/C3/C4/C5/C6) and pyrazine ring (C1/C6/N1/N2/C7/C8) is 1.46 (11)%. The planer ester moiety attached to the C8 is oriented at dihedral angle of 5.70 (14)% and 7.13 (13)% with respect to the aomatic and pyrazine rings respectively. The cyclic carboxamide functional group from the pyrazine rings forms dimers through N—H···O type hydrogen bonding interaction which further connects through weak C—H···O type hydrogen bonding interaction to form the polymeric chain along b axes (Fig. 2 Table 1).

Experimental

To the suspension of 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoic acid (Taylor et al., 1965) (5 g, 0.023 mol) in absolute ethanol (100 ml) was added 3N H₂SO₄ (10 ml) and reaction mixture was refluxed for four hours. Solution was then concentrated under reduced pressure and neutralized with sodium bicarbonate solution to dissolve any unreacted acid. The precipitates were filtered under reduced pressure and washed with excess of water. The resulting ester was then recrystallized in absolute ethanol to yield colourless needles of (I). The product melted at 173-175 C (lit mp 160-162 C). (95% yield).