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ISSN: 2056-9890

Ethyl 8-(4-nitro­phen­yl)imidazo[1,2-a]pyridine-7-carboxyl­ate

aCollege of Pharmaceutical Sciences, Taishan Medical University, Tai an 271016, People's Republic of China
*Correspondence e-mail: duanguiyun@yahoo.cn

(Received 12 November 2010; accepted 17 November 2010; online 24 November 2010)

In the title compound, C16H13N3O4, the imidazo[1,2-a]pyridine and benzene rings make a dihedral angle of 56.21 (2)°. The crystal packing is stabilized by weak ππ stacking inter­actions [centroid–centroid distances = 3.787 (2) Å] and C—H⋯O inter­molecular hydrogen-bonding inter­actions.

Related literature

For applications of imidazo[1,2-a]pyridine-containing compounds, see: Jia et al. (2010[Jia, J., Ge, Y. Q., Tao, X. T. & Wang, J. W. (2010). Heterocycles, 81, 185-794.]).

[Scheme 1]

Experimental

Crystal data
  • C16H13N3O4

  • Mr = 311.29

  • Monoclinic, P 21 /c

  • a = 8.189 (4) Å

  • b = 15.821 (8) Å

  • c = 11.884 (6) Å

  • β = 105.380 (8)°

  • V = 1484.7 (13) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 273 K

  • 0.26 × 0.19 × 0.13 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.974, Tmax = 0.987

  • 7569 measured reflections

  • 2618 independent reflections

  • 1965 reflections with I > 2σ(I)

  • Rint = 0.023

Refinement
  • R[F2 > 2σ(F2)] = 0.042

  • wR(F2) = 0.122

  • S = 1.38

  • 2618 reflections

  • 209 parameters

  • H-atom parameters constrained

  • Δρmax = 0.18 e Å−3

  • Δρmin = −0.16 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C9—H9B⋯O3i 0.97 2.59 3.295 (3) 130
Symmetry code: (i) -x, -y, -z.

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1999[Bruker (1999). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The imidazo[1,2-a]pyridines (IP) have attracted considerable attention because of their wide range of pharmacological activities such as antiviral, antibacterial, antifungal, antiulcer, and anti-inflammatory behavior (Jia et al., 2010). Drugs containing imidazo[1,2-a]pyridines such as Alpidem, Zolpidem, Necopidem, Olprinone, Divalpon and Zolimidine are currently available on the market. In continuation of our work in this direction, we report here the crystal structure of the title compound, (I).

The title compound, C16H13N3O4, the imidazo[1,2-a]pyridine ring (N2/N3/C1—C7) and benzene ring (C11—C16) make a dihedral angles of 56.21 (2) °. ππ interactions are indicated by the short distance (Cg1···Cg2 distance of 3.787 (2) Å, symmetry code: x,1/2 - y,-1/2 + z) between the centroids of the pyridine ring (N2/C3—C7) (Cg1) and benzene ring C11—C16 (Cg2) (Table 1). There are weaker C—H···O intermolecular interactions, which stabilize the structure (Table 1).

Related literature top

For applications of imidazo[1,2-a]pyridine-containing compounds, see: Jia et al. (2010).

Experimental top

To a 50-ml round-bottomed flask were added ethyl 4-bromobut-2-enoate (1.20 mmol), (1H-imidazol-2-yl)(4-nitrophenyl)methanone (1.00 mmol), potassium carbonate (0.283 g, 2.05 mmol) and dry DMF (10 ml). The mixture was stirred at rt for 3 h and then filtered. The filtrate was poured into water (100 ml) and extracted with CH2Cl2 (three times per 30 ml). The combined extracts were washed with water, dried over anhydrous MgSO4 and filtered, and the solvent was removed by rotary evaporation. The crude product were purified by column chromatography. Crystals of (I) suitable for X-ray diffraction was obtained by slow evaporation of a solution of the product in ethyl acetate at room temperature for 2 d.

Refinement top

H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 or 0.97Å and with Uiso(H) = 1.2Ueq(C) and 1.5Ueq(C) for methyl H atoms.

Structure description top

The imidazo[1,2-a]pyridines (IP) have attracted considerable attention because of their wide range of pharmacological activities such as antiviral, antibacterial, antifungal, antiulcer, and anti-inflammatory behavior (Jia et al., 2010). Drugs containing imidazo[1,2-a]pyridines such as Alpidem, Zolpidem, Necopidem, Olprinone, Divalpon and Zolimidine are currently available on the market. In continuation of our work in this direction, we report here the crystal structure of the title compound, (I).

The title compound, C16H13N3O4, the imidazo[1,2-a]pyridine ring (N2/N3/C1—C7) and benzene ring (C11—C16) make a dihedral angles of 56.21 (2) °. ππ interactions are indicated by the short distance (Cg1···Cg2 distance of 3.787 (2) Å, symmetry code: x,1/2 - y,-1/2 + z) between the centroids of the pyridine ring (N2/C3—C7) (Cg1) and benzene ring C11—C16 (Cg2) (Table 1). There are weaker C—H···O intermolecular interactions, which stabilize the structure (Table 1).

For applications of imidazo[1,2-a]pyridine-containing compounds, see: Jia et al. (2010).

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. View of the title compound (I), with displacement ellipsoids drawn at the 40% probability level.
Ethyl 8-(4-nitrophenyl)imidazo[1,2-a]pyridine-7-carboxylate top
Crystal data top
C16H13N3O4F(000) = 648
Mr = 311.29Dx = 1.393 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2224 reflections
a = 8.189 (4) Åθ = 2.2–28.2°
b = 15.821 (8) ŵ = 0.10 mm1
c = 11.884 (6) ÅT = 273 K
β = 105.380 (8)°Block, colorless
V = 1484.7 (13) Å30.26 × 0.19 × 0.13 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
2618 independent reflections
Radiation source: fine-focus sealed tube1965 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
phi and ω scansθmax = 25.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.974, Tmax = 0.987k = 1814
7569 measured reflectionsl = 1314
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.042H-atom parameters constrained
wR(F2) = 0.122 w = 1/[σ2(Fo2) + (0.0514P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.38(Δ/σ)max = 0.014
2618 reflectionsΔρmax = 0.18 e Å3
209 parametersΔρmin = 0.16 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.018 (2)
Crystal data top
C16H13N3O4V = 1484.7 (13) Å3
Mr = 311.29Z = 4
Monoclinic, P21/cMo Kα radiation
a = 8.189 (4) ŵ = 0.10 mm1
b = 15.821 (8) ÅT = 273 K
c = 11.884 (6) Å0.26 × 0.19 × 0.13 mm
β = 105.380 (8)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
2618 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1965 reflections with I > 2σ(I)
Tmin = 0.974, Tmax = 0.987Rint = 0.023
7569 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0420 restraints
wR(F2) = 0.122H-atom parameters constrained
S = 1.38Δρmax = 0.18 e Å3
2618 reflectionsΔρmin = 0.16 e Å3
209 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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) top
xyzUiso*/Ueq
O10.4896 (3)0.09876 (13)0.56705 (14)0.1106 (7)
O20.2458 (2)0.15378 (13)0.49165 (14)0.1073 (7)
O30.26198 (16)0.02576 (9)0.02277 (12)0.0718 (4)
O40.16766 (15)0.07201 (9)0.15928 (11)0.0664 (4)
N10.3843 (3)0.12901 (12)0.48549 (16)0.0745 (5)
N20.72970 (16)0.19702 (9)0.06373 (12)0.0490 (4)
N30.80707 (17)0.22853 (10)0.12673 (13)0.0561 (4)
C10.8789 (2)0.24074 (12)0.04309 (17)0.0604 (5)
H10.93810.25500.09720.073*
C20.9223 (2)0.25889 (13)0.07191 (18)0.0617 (5)
H21.01930.28860.10960.074*
C30.6901 (2)0.19066 (11)0.04239 (14)0.0460 (4)
C40.53881 (19)0.14865 (10)0.04674 (14)0.0432 (4)
C50.4368 (2)0.11716 (11)0.05585 (14)0.0456 (4)
C60.4823 (2)0.12748 (12)0.16214 (14)0.0521 (5)
H60.41080.10700.23110.063*
C70.6262 (2)0.16622 (12)0.16469 (15)0.0550 (5)
H70.65550.17210.23470.066*
C80.2819 (2)0.06715 (11)0.05705 (15)0.0500 (4)
C90.0130 (2)0.02350 (15)0.17049 (19)0.0762 (6)
H9A0.04050.03490.14840.091*
H9B0.05090.04670.11970.091*
C100.0864 (3)0.02810 (19)0.2914 (2)0.1084 (9)
H10A0.11000.08620.31300.163*
H10B0.19090.00190.30030.163*
H10C0.02380.00310.34070.163*
C110.4992 (2)0.14378 (10)0.16178 (13)0.0444 (4)
C120.6133 (2)0.10865 (12)0.25694 (14)0.0534 (5)
H120.71590.08790.24900.064*
C130.5773 (2)0.10392 (12)0.36384 (15)0.0576 (5)
H130.65410.08010.42800.069*
C140.4254 (3)0.13518 (12)0.37291 (15)0.0551 (5)
C150.3104 (2)0.17153 (12)0.28087 (17)0.0606 (5)
H150.20890.19310.28970.073*
C160.3482 (2)0.17554 (12)0.17493 (15)0.0551 (5)
H160.27110.19990.11140.066*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.1407 (15)0.1542 (18)0.0415 (9)0.0163 (13)0.0320 (10)0.0017 (10)
O20.1239 (15)0.1407 (17)0.0844 (12)0.0061 (12)0.0754 (11)0.0159 (10)
O30.0773 (9)0.0782 (10)0.0643 (9)0.0097 (7)0.0263 (7)0.0181 (7)
O40.0542 (8)0.0928 (11)0.0517 (8)0.0126 (7)0.0132 (6)0.0050 (7)
N10.1072 (15)0.0807 (13)0.0470 (11)0.0257 (11)0.0407 (11)0.0149 (9)
N20.0456 (8)0.0610 (9)0.0463 (9)0.0069 (7)0.0227 (7)0.0053 (7)
N30.0464 (9)0.0705 (11)0.0539 (9)0.0020 (7)0.0180 (8)0.0055 (8)
C10.0479 (11)0.0750 (13)0.0668 (13)0.0025 (9)0.0298 (10)0.0064 (10)
C20.0440 (10)0.0723 (13)0.0731 (14)0.0006 (9)0.0230 (10)0.0030 (10)
C30.0459 (10)0.0546 (10)0.0422 (10)0.0116 (8)0.0199 (8)0.0030 (8)
C40.0446 (9)0.0490 (10)0.0405 (9)0.0096 (7)0.0193 (8)0.0046 (7)
C50.0484 (9)0.0523 (10)0.0397 (10)0.0070 (8)0.0179 (8)0.0038 (8)
C60.0534 (10)0.0671 (12)0.0383 (10)0.0034 (9)0.0166 (8)0.0020 (8)
C70.0609 (11)0.0726 (13)0.0382 (10)0.0078 (9)0.0247 (9)0.0057 (9)
C80.0550 (11)0.0536 (11)0.0463 (11)0.0053 (8)0.0221 (9)0.0001 (8)
C90.0588 (12)0.0869 (16)0.0848 (17)0.0171 (11)0.0225 (11)0.0004 (12)
C100.0882 (18)0.117 (2)0.102 (2)0.0324 (16)0.0065 (15)0.0071 (16)
C110.0499 (10)0.0496 (10)0.0381 (9)0.0030 (8)0.0192 (8)0.0013 (7)
C120.0544 (10)0.0637 (12)0.0454 (10)0.0073 (9)0.0186 (9)0.0024 (8)
C130.0681 (12)0.0668 (12)0.0369 (10)0.0044 (10)0.0120 (9)0.0033 (8)
C140.0756 (13)0.0571 (11)0.0410 (10)0.0129 (10)0.0302 (9)0.0087 (8)
C150.0675 (12)0.0658 (12)0.0605 (12)0.0065 (10)0.0380 (10)0.0009 (10)
C160.0573 (11)0.0651 (12)0.0500 (11)0.0121 (9)0.0269 (9)0.0087 (9)
Geometric parameters (Å, º) top
O1—N11.212 (2)C6—C71.336 (2)
O2—N11.221 (2)C6—H60.9300
O3—C81.199 (2)C7—H70.9300
O4—C81.324 (2)C9—C101.453 (3)
O4—C91.456 (2)C9—H9A0.9700
N1—C141.467 (2)C9—H9B0.9700
N2—C71.362 (2)C10—H10A0.9600
N2—C11.368 (2)C10—H10B0.9600
N2—C31.387 (2)C10—H10C0.9600
N3—C31.331 (2)C11—C121.379 (2)
N3—C21.368 (2)C11—C161.382 (2)
C1—C21.349 (3)C12—C131.380 (2)
C1—H10.9300C12—H120.9300
C2—H20.9300C13—C141.369 (3)
C3—C41.419 (2)C13—H130.9300
C4—C51.376 (2)C14—C151.367 (3)
C4—C111.488 (2)C15—C161.375 (2)
C5—C61.418 (2)C15—H150.9300
C5—C81.492 (2)C16—H160.9300
C8—O4—C9116.01 (15)O4—C8—C5111.70 (14)
O1—N1—O2123.67 (18)C10—C9—O4108.03 (18)
O1—N1—C14118.0 (2)C10—C9—H9A110.1
O2—N1—C14118.4 (2)O4—C9—H9A110.1
C7—N2—C1131.00 (15)C10—C9—H9B110.1
C7—N2—C3122.27 (14)O4—C9—H9B110.1
C1—N2—C3106.67 (15)H9A—C9—H9B108.4
C3—N3—C2104.42 (15)C9—C10—H10A109.5
C2—C1—N2105.78 (16)C9—C10—H10B109.5
C2—C1—H1127.1H10A—C10—H10B109.5
N2—C1—H1127.1C9—C10—H10C109.5
C1—C2—N3112.23 (17)H10A—C10—H10C109.5
C1—C2—H2123.9H10B—C10—H10C109.5
N3—C2—H2123.9C12—C11—C16119.08 (15)
N3—C3—N2110.90 (14)C12—C11—C4120.61 (15)
N3—C3—C4130.12 (15)C16—C11—C4120.30 (14)
N2—C3—C4118.97 (15)C11—C12—C13120.87 (16)
C5—C4—C3117.92 (14)C11—C12—H12119.6
C5—C4—C11124.50 (15)C13—C12—H12119.6
C3—C4—C11117.56 (15)C14—C13—C12118.25 (17)
C4—C5—C6120.44 (16)C14—C13—H13120.9
C4—C5—C8121.03 (14)C12—C13—H13120.9
C6—C5—C8118.43 (15)C15—C14—C13122.45 (16)
C7—C6—C5120.98 (17)C15—C14—N1118.81 (18)
C7—C6—H6119.5C13—C14—N1118.74 (19)
C5—C6—H6119.5C14—C15—C16118.54 (17)
C6—C7—N2119.39 (15)C14—C15—H15120.7
C6—C7—H7120.3C16—C15—H15120.7
N2—C7—H7120.3C15—C16—C11120.80 (17)
O3—C8—O4123.14 (17)C15—C16—H16119.6
O3—C8—C5125.15 (17)C11—C16—H16119.6
C7—N2—C1—C2177.07 (17)C9—O4—C8—C5178.48 (15)
C3—N2—C1—C20.19 (19)C4—C5—C8—O327.4 (3)
N2—C1—C2—N30.1 (2)C6—C5—C8—O3149.05 (18)
C3—N3—C2—C10.1 (2)C4—C5—C8—O4154.15 (15)
C2—N3—C3—N20.17 (18)C6—C5—C8—O429.4 (2)
C2—N3—C3—C4179.10 (17)C8—O4—C9—C10173.05 (19)
C7—N2—C3—N3177.32 (15)C5—C4—C11—C12125.59 (19)
C1—N2—C3—N30.23 (18)C3—C4—C11—C1256.1 (2)
C7—N2—C3—C41.7 (2)C5—C4—C11—C1655.3 (2)
C1—N2—C3—C4179.30 (14)C3—C4—C11—C16122.98 (19)
N3—C3—C4—C5177.88 (16)C16—C11—C12—C130.9 (3)
N2—C3—C4—C51.0 (2)C4—C11—C12—C13179.97 (16)
N3—C3—C4—C110.5 (3)C11—C12—C13—C140.1 (3)
N2—C3—C4—C11179.36 (13)C12—C13—C14—C150.9 (3)
C3—C4—C5—C60.5 (2)C12—C13—C14—N1178.82 (16)
C11—C4—C5—C6177.72 (15)O1—N1—C14—C15177.96 (19)
C3—C4—C5—C8175.81 (14)O2—N1—C14—C152.7 (3)
C11—C4—C5—C85.9 (2)O1—N1—C14—C132.4 (3)
C4—C5—C6—C71.4 (3)O2—N1—C14—C13176.97 (18)
C8—C5—C6—C7175.01 (16)C13—C14—C15—C161.0 (3)
C5—C6—C7—N20.7 (3)N1—C14—C15—C16178.65 (17)
C1—N2—C7—C6177.78 (17)C14—C15—C16—C110.2 (3)
C3—N2—C7—C60.9 (2)C12—C11—C16—C150.7 (3)
C9—O4—C8—O30.0 (3)C4—C11—C16—C15179.87 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C9—H9B···O3i0.972.593.295 (3)130
Symmetry code: (i) x, y, z.

Experimental details

Crystal data
Chemical formulaC16H13N3O4
Mr311.29
Crystal system, space groupMonoclinic, P21/c
Temperature (K)273
a, b, c (Å)8.189 (4), 15.821 (8), 11.884 (6)
β (°) 105.380 (8)
V3)1484.7 (13)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.26 × 0.19 × 0.13
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.974, 0.987
No. of measured, independent and
observed [I > 2σ(I)] reflections
7569, 2618, 1965
Rint0.023
(sin θ/λ)max1)0.596
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.042, 0.122, 1.38
No. of reflections2618
No. of parameters209
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.18, 0.16

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C9—H9B···O3i0.972.593.295 (3)130.2
Symmetry code: (i) x, y, z.
 

Acknowledgements

This work was supported by the Natural Science Fund of Shandong Province (Y2007C135).

References

First citationBruker (1998). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (1999). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationJia, J., Ge, Y. Q., Tao, X. T. & Wang, J. W. (2010). Heterocycles, 81, 185–794.  CAS Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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