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Acta Crystallogr Sect E Struct Rep Online. 2009 December 1; 65(Pt 12): o3006.
Published online 2009 November 7. doi:  10.1107/S1600536809045991
PMCID: PMC2971779

4-[(2,5-Dimethyl­anilino)acet­yl]-3,4-di­hydro­quinoxalin-2(1H)-one

Abstract

In the title compound, C18H19N3O2, the dihedral angle between the benzene rings is 20.47 (10)° and an intra­molecular N—H(...)O hydrogen bond occurs, generating an S(5) ring. In the crystal, inversion dimers linked by pairs of N—H(...)O hydrogen bonds lead to R 2 2(8) loops.

Related literature

For background to the biological activity of quinoxalines, see: Khan (2008 [triangle]); Miyashiro et al. (2009 [triangle]). For graph-set notation, see: Bernstein et al. (1995 [triangle]).

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Object name is e-65-o3006-scheme1.jpg

Experimental

Crystal data

  • C18H19N3O2
  • M r = 309.36
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o3006-efi1.jpg
  • a = 5.3806 (2) Å
  • b = 12.3580 (6) Å
  • c = 13.2812 (6) Å
  • α = 62.878 (2)°
  • β = 84.135 (2)°
  • γ = 80.835 (3)°
  • V = 775.53 (6) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 296 K
  • 0.38 × 0.17 × 0.06 mm

Data collection

  • Bruker Kappa APEXII CCD diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2007 [triangle]) T min = 0.967, T max = 0.995
  • 16710 measured reflections
  • 3803 independent reflections
  • 2277 reflections with I > 2σ(I)
  • R int = 0.032

Refinement

  • R[F 2 > 2σ(F 2)] = 0.048
  • wR(F 2) = 0.140
  • S = 1.02
  • 3803 reflections
  • 216 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.21 e Å−3
  • Δρmin = −0.17 e Å−3

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

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809045991/hb5210sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809045991/hb5210Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

WN acknowledges the Higher Education Commission, Pakistan, for providing funding for this research.

supplementary crystallographic information

Comment

Quinoxalines represent an important class of nitrogen hetrocycles possessing wide range of biological activities (e.g. Khan, 2008). Moreover, several quinoxalines have been reported as inhibitors of, e.g. poly(ADP-ribose)polymerase-1 (Miyashiro et al., 2009). During our research we tried to synthesize novel quinoxaline derivatives which may possess enhanced biological activities.

The pyrazinone ring in the quinoxaline system have gained envelop shape to some extent with the r.m.s. deviation (0.1637 A°). The intramolecular hydrogen bonding present in the molecule give rise to the formation of five membered ring motif S(5) (Bernstein, et al., 1995) which is oriented at a dihedral angle of 28.13 (0.24) ° with respect to pyrazinone ring. The dihedral angle between planar p-xylene and pyrazinone ring is 21.31 (0.09) °. Further more symmetry related N–H···O type hydrogen bonding helps to stabilize the crystal structure of the molecule by forming eight membered ring motif R228.

Experimental

2,5 Dimethyl aniline (0.67 g, 5.57 mmol) added to the suspension of 4-(Chloroacetyl)-3,4-dihydroquinoxalin-2 (1H)-one (1.25 g, 5.57 mmol and NaHCO3 (0.7 g, 8.35 mmol) in 2-propanol. The reaction mixture was refluxed for 8 h. Then reaction was monitored by TLC (CHCl3 and ethylacetate). The solid obtained on cooling was filtered, washed with chloroform and methanol. Colourless chunks of (I) were grown from an acetone DMF mixture by slow evaporation at room temperature.

Refinement

The H-atoms for the aromatic (C—H = 0.93), methylene (C—H = 0.97) and methyl carbon (C—H = 0.96) atoms were geometrically placed and treated as riding atoms: with Uiso(H) = 1.2Ueq for aromatic and methylene carbon atoms and Uiso(H) = 1.5Ueq for methyl carbon atoms. The (N—H 0.85 (2)–0.91 (2) atoms were freely refined with Uiso(H) = 1.2Ueq (parent N-atom)

Figures

Fig. 1.
The molecular structure of (I) showing 50% displacement ellipsoids.
Fig. 2.
Packing diagram for (I) showing the intermolecular and intramolecular hydrogen bonding using dashed lines. The hydrogen atoms not involved in hydrogen bonding have been omitted for clarity.

Crystal data

C18H19N3O2Z = 2
Mr = 309.36F(000) = 328
Triclinic, P1Dx = 1.325 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.3806 (2) ÅCell parameters from 3605 reflections
b = 12.3580 (6) Åθ = 3.1–25.1°
c = 13.2812 (6) ŵ = 0.09 mm1
α = 62.878 (2)°T = 296 K
β = 84.135 (2)°Chunk, colourless
γ = 80.835 (3)°0.38 × 0.17 × 0.06 mm
V = 775.53 (6) Å3

Data collection

Bruker Kappa APEXII CCD diffractometer3803 independent reflections
Radiation source: fine-focus sealed tube2277 reflections with I > 2σ(I)
graphiteRint = 0.032
[var phi] and ω scansθmax = 28.3°, θmin = 3.1°
Absorption correction: multi-scan (SADABS; Bruker, 2007)h = −7→7
Tmin = 0.967, Tmax = 0.995k = −16→16
16710 measured reflectionsl = −17→17

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.140H atoms treated by a mixture of independent and constrained refinement
S = 1.02w = 1/[σ2(Fo2) + (0.0583P)2 + 0.1485P] where P = (Fo2 + 2Fc2)/3
3803 reflections(Δ/σ)max < 0.001
216 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = −0.17 e Å3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
C10.3267 (3)−0.03248 (15)0.21118 (13)0.0375 (4)
C20.2304 (3)−0.09075 (17)0.15875 (15)0.0474 (4)
H20.2528−0.06320.08090.057*
C30.1012 (4)−0.18983 (18)0.22234 (17)0.0565 (5)
H30.0350−0.22830.18700.068*
C40.0695 (4)−0.23204 (18)0.33759 (17)0.0595 (5)
H4−0.0191−0.29840.37980.071*
C50.1690 (3)−0.17607 (17)0.39049 (15)0.0527 (5)
H50.1486−0.20500.46850.063*
C60.2993 (3)−0.07679 (15)0.32755 (13)0.0402 (4)
C70.5923 (3)0.04788 (16)0.33477 (14)0.0432 (4)
C80.6625 (3)0.07691 (18)0.21398 (13)0.0478 (5)
H8A0.71480.15810.17600.057*
H8B0.80510.01900.21190.057*
C90.3822 (3)0.16519 (16)0.05055 (13)0.0394 (4)
C100.5334 (3)0.27254 (16)−0.00272 (13)0.0441 (4)
H10A0.51180.31700.04240.053*
H10B0.71100.2433−0.00600.053*
C110.5571 (3)0.45478 (16)−0.18728 (14)0.0446 (4)
C120.4976 (3)0.51241 (17)−0.30190 (15)0.0487 (4)
C130.6002 (4)0.61824 (19)−0.37152 (17)0.0605 (5)
H130.56290.6575−0.44780.073*
C140.7563 (4)0.66854 (19)−0.33251 (18)0.0630 (6)
H140.81780.7415−0.38190.076*
C150.8211 (3)0.61092 (17)−0.22080 (17)0.0521 (5)
C160.7209 (3)0.50364 (17)−0.14910 (15)0.0487 (4)
H160.76430.4633−0.07350.058*
C170.9978 (4)0.6614 (2)−0.1771 (2)0.0713 (6)
H17A0.94900.6454−0.10050.107*
H17B0.99070.7483−0.22350.107*
H17C1.16640.6229−0.17950.107*
C180.3267 (4)0.4598 (2)−0.34590 (16)0.0609 (5)
H18A0.39820.3782−0.33240.091*
H18B0.30800.5101−0.42570.091*
H18C0.16480.4573−0.30770.091*
N10.4033 (3)−0.02041 (14)0.38128 (12)0.0479 (4)
N20.4571 (2)0.07258 (12)0.15222 (11)0.0388 (3)
N30.4475 (3)0.35148 (15)−0.11433 (13)0.0580 (5)
O10.7078 (2)0.08343 (13)0.38634 (10)0.0589 (4)
O20.2018 (2)0.16278 (12)0.00335 (10)0.0550 (4)
H1N0.366 (4)−0.0432 (18)0.4561 (19)0.066*
H2N0.339 (4)0.3255 (19)−0.1377 (17)0.066*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0355 (8)0.0409 (9)0.0372 (9)−0.0074 (7)−0.0020 (6)−0.0174 (7)
C20.0535 (10)0.0532 (11)0.0437 (10)−0.0114 (8)−0.0022 (8)−0.0272 (9)
C30.0680 (12)0.0528 (11)0.0600 (12)−0.0194 (10)−0.0072 (9)−0.0305 (10)
C40.0696 (13)0.0527 (12)0.0557 (12)−0.0274 (10)−0.0070 (10)−0.0167 (10)
C50.0595 (11)0.0560 (12)0.0393 (10)−0.0209 (9)−0.0047 (8)−0.0137 (9)
C60.0400 (9)0.0454 (10)0.0383 (9)−0.0101 (7)−0.0055 (7)−0.0191 (8)
C70.0443 (9)0.0476 (10)0.0390 (9)−0.0101 (8)−0.0091 (7)−0.0175 (8)
C80.0396 (9)0.0648 (12)0.0395 (10)−0.0183 (8)−0.0044 (7)−0.0194 (9)
C90.0400 (9)0.0481 (10)0.0342 (9)−0.0092 (7)−0.0001 (7)−0.0211 (8)
C100.0457 (9)0.0514 (11)0.0371 (9)−0.0142 (8)−0.0029 (7)−0.0187 (8)
C110.0459 (10)0.0438 (10)0.0424 (10)−0.0066 (8)−0.0030 (7)−0.0173 (8)
C120.0508 (10)0.0496 (11)0.0418 (10)−0.0020 (8)−0.0040 (8)−0.0181 (8)
C130.0656 (13)0.0581 (12)0.0431 (11)−0.0049 (10)−0.0028 (9)−0.0106 (9)
C140.0669 (13)0.0493 (12)0.0608 (13)−0.0165 (10)0.0107 (10)−0.0142 (10)
C150.0487 (10)0.0501 (11)0.0614 (12)−0.0123 (8)0.0078 (9)−0.0284 (10)
C160.0520 (10)0.0515 (11)0.0437 (10)−0.0136 (9)−0.0019 (8)−0.0200 (9)
C170.0663 (13)0.0734 (15)0.0898 (17)−0.0316 (11)0.0121 (12)−0.0459 (13)
C180.0656 (12)0.0696 (14)0.0475 (11)−0.0066 (10)−0.0132 (9)−0.0247 (10)
N10.0548 (9)0.0629 (10)0.0327 (8)−0.0240 (8)0.0006 (6)−0.0224 (7)
N20.0381 (7)0.0471 (8)0.0331 (7)−0.0131 (6)−0.0024 (5)−0.0169 (6)
N30.0679 (11)0.0545 (10)0.0456 (9)−0.0250 (8)−0.0165 (8)−0.0090 (8)
O10.0667 (8)0.0757 (9)0.0453 (7)−0.0334 (7)−0.0050 (6)−0.0283 (7)
O20.0546 (7)0.0619 (8)0.0449 (7)−0.0206 (6)−0.0148 (6)−0.0140 (6)

Geometric parameters (Å, °)

C1—C61.385 (2)C10—H10A0.9700
C1—C21.386 (2)C10—H10B0.9700
C1—N21.4290 (19)C11—N31.383 (2)
C2—C31.380 (2)C11—C161.392 (2)
C2—H20.9300C11—C121.402 (2)
C3—C41.375 (3)C12—C131.376 (3)
C3—H30.9300C12—C181.502 (2)
C4—C51.377 (2)C13—C141.382 (3)
C4—H40.9300C13—H130.9300
C5—C61.384 (2)C14—C151.376 (3)
C5—H50.9300C14—H140.9300
C6—N11.402 (2)C15—C161.388 (2)
C7—O11.2233 (18)C15—C171.504 (3)
C7—N11.341 (2)C16—H160.9300
C7—C81.496 (2)C17—H17A0.9600
C8—N21.4632 (18)C17—H17B0.9600
C8—H8A0.9700C17—H17C0.9600
C8—H8B0.9700C18—H18A0.9600
C9—O21.2192 (17)C18—H18B0.9600
C9—N21.361 (2)C18—H18C0.9600
C9—C101.514 (2)N1—H1N0.91 (2)
C10—N31.429 (2)N3—H2N0.85 (2)
C6—C1—C2119.61 (15)C16—C11—C12119.56 (16)
C6—C1—N2116.51 (13)C13—C12—C11117.64 (17)
C2—C1—N2123.89 (15)C13—C12—C18121.72 (17)
C3—C2—C1119.81 (16)C11—C12—C18120.64 (16)
C3—C2—H2120.1C12—C13—C14122.58 (18)
C1—C2—H2120.1C12—C13—H13118.7
C4—C3—C2120.47 (16)C14—C13—H13118.7
C4—C3—H3119.8C15—C14—C13120.20 (18)
C2—C3—H3119.8C15—C14—H14119.9
C3—C4—C5120.01 (17)C13—C14—H14119.9
C3—C4—H4120.0C14—C15—C16118.20 (17)
C5—C4—H4120.0C14—C15—C17121.24 (18)
C4—C5—C6119.99 (17)C16—C15—C17120.56 (18)
C4—C5—H5120.0C15—C16—C11121.77 (17)
C6—C5—H5120.0C15—C16—H16119.1
C5—C6—C1120.08 (15)C11—C16—H16119.1
C5—C6—N1120.15 (15)C15—C17—H17A109.5
C1—C6—N1119.77 (14)C15—C17—H17B109.5
O1—C7—N1123.53 (16)H17A—C17—H17B109.5
O1—C7—C8120.51 (15)C15—C17—H17C109.5
N1—C7—C8115.94 (14)H17A—C17—H17C109.5
N2—C8—C7113.34 (13)H17B—C17—H17C109.5
N2—C8—H8A108.9C12—C18—H18A109.5
C7—C8—H8A108.9C12—C18—H18B109.5
N2—C8—H8B108.9H18A—C18—H18B109.5
C7—C8—H8B108.9C12—C18—H18C109.5
H8A—C8—H8B107.7H18A—C18—H18C109.5
O2—C9—N2122.03 (15)H18B—C18—H18C109.5
O2—C9—C10120.83 (15)C7—N1—C6122.90 (15)
N2—C9—C10117.14 (13)C7—N1—H1N116.9 (12)
N3—C10—C9108.72 (12)C6—N1—H1N118.9 (12)
N3—C10—H10A109.9C9—N2—C1122.08 (12)
C9—C10—H10A109.9C9—N2—C8123.03 (13)
N3—C10—H10B109.9C1—N2—C8114.71 (13)
C9—C10—H10B109.9C11—N3—C10122.78 (14)
H10A—C10—H10B108.3C11—N3—H2N120.7 (14)
N3—C11—C16121.54 (16)C10—N3—H2N115.9 (14)
N3—C11—C12118.89 (16)
C6—C1—C2—C32.1 (3)C13—C14—C15—C17177.88 (19)
N2—C1—C2—C3−178.28 (16)C14—C15—C16—C11−0.6 (3)
C1—C2—C3—C4−0.7 (3)C17—C15—C16—C11−179.95 (17)
C2—C3—C4—C5−0.6 (3)N3—C11—C16—C15−176.58 (18)
C3—C4—C5—C60.5 (3)C12—C11—C16—C152.3 (3)
C4—C5—C6—C10.9 (3)O1—C7—N1—C6−169.54 (17)
C4—C5—C6—N1−179.29 (17)C8—C7—N1—C68.9 (3)
C2—C1—C6—C5−2.2 (3)C5—C6—N1—C7158.51 (17)
N2—C1—C6—C5178.14 (15)C1—C6—N1—C7−21.7 (3)
C2—C1—C6—N1178.03 (16)O2—C9—N2—C1−1.1 (3)
N2—C1—C6—N1−1.6 (2)C10—C9—N2—C1179.09 (14)
O1—C7—C8—N2−157.17 (17)O2—C9—N2—C8−175.90 (16)
N1—C7—C8—N224.4 (2)C10—C9—N2—C84.3 (2)
O2—C9—C10—N3−7.3 (2)C6—C1—N2—C9−140.30 (16)
N2—C9—C10—N3172.49 (15)C2—C1—N2—C940.0 (2)
N3—C11—C12—C13177.03 (18)C6—C1—N2—C834.9 (2)
C16—C11—C12—C13−1.9 (3)C2—C1—N2—C8−144.75 (17)
N3—C11—C12—C18−2.7 (3)C7—C8—N2—C9129.03 (17)
C16—C11—C12—C18178.41 (17)C7—C8—N2—C1−46.1 (2)
C11—C12—C13—C14−0.2 (3)C16—C11—N3—C10−14.3 (3)
C18—C12—C13—C14179.55 (19)C12—C11—N3—C10166.82 (18)
C12—C13—C14—C151.9 (3)C9—C10—N3—C11−176.65 (17)
C13—C14—C15—C16−1.5 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N3—H2N···O20.85 (2)2.20 (2)2.620 (2)110.0 (16)
N1—H1N···O1i0.91 (2)1.93 (2)2.8405 (19)176.9 (18)

Symmetry codes: (i) −x+1, −y, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB5210).

References

  • Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.
  • Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
  • Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
  • Khan, A. S. (2008). Eur. J. Med. Chem 43, 2040–2044. [PubMed]
  • Miyashiro, J., Woods, K. W., Park, C. H., Liu, X., Shi, Y., Johnson, E. F., Bouska, J. J., Olson, A. M., Luo, Y., Fry, E. H., Giranda, V. L. & Penning, T. D. (2009). Bioorg. Med. Chem. Lett. 19, 4050-4054. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography