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Acta Crystallogr Sect E Struct Rep Online. 2009 October 1; 65(Pt 10): o2476–o2477.
Published online 2009 September 16. doi:  10.1107/S160053680903654X
PMCID: PMC2970413

(E)-1-Ethyl-4-oxo-N′-(4-pyridylmethyl­ene)-1,4-dihydroquinoline-3-carbo­hydrazide

Abstract

In the title compound, C18H16N4O2, the plane defined by the ethyl C atoms and the attached N atom is inclined to the adjacent pyridine ring at an angle of 67.87 (16)°. The dihedral angle between the two heterocyclic rings is 3.33 (16)°. The mol­ecular conformation is stabilized by an intra­molecular N—H(...)O hydrogen bond and the crystal structure by inter­molecular C—H(...)O hydrogen bonds, forming a one-dimensional structure.

Related literature

For the biological properties of oxoquinoline derivatives, see: Van Bambeke et al. (2005 [triangle]); Canuto et al. (2007 [triangle]); Lucero et al. (2006 [triangle]). For their potential use in the treatment of fungal and viral infections, see: Brideau et al. (2002 [triangle]); Souza et al. (2008 [triangle]) and in cancer chemotherapy, see: Chu et al. (1992 [triangle]). For acyl­hydrazones and their anti­leishmanial activity, see: Bernadino et al. (2006 [triangle]); Cunha et al. (2003 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]).

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Object name is e-65-o2476-scheme1.jpg

Experimental

Crystal data

  • C18H16N4O2
  • M r = 320.35
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2476-efi1.jpg
  • a = 7.6460 (12) Å
  • b = 19.205 (2) Å
  • c = 10.7050 (9) Å
  • β = 99.722 (10)°
  • V = 1549.4 (3) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 293 K
  • 0.5 × 0.2 × 0.2 mm

Data collection

  • Nonius KappaCCD diffractometer
  • Absorption correction: none
  • 7914 measured reflections
  • 2586 independent reflections
  • 2001 reflections with I > 2σ(I)
  • R int = 0.019

Refinement

  • R[F 2 > 2σ(F 2)] = 0.041
  • wR(F 2) = 0.102
  • S = 1.07
  • 2586 reflections
  • 222 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.13 e Å−3
  • Δρmin = −0.15 e Å−3

Data collection: COLLECT (Nonius, 2000 [triangle]); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997 [triangle]); data reduction: HKL DENZO (Otwinowski & Minor 1997 [triangle]) and SCALEPACK; program(s) used to solve structure: SIR2002 (Burla et al., 2003 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEP-3 (Farrugia, 1997 [triangle]) and Mercury (Macrae et al., 2008 [triangle]); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680903654X/wn2340sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903654X/wn2340Isup2.hkl

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

Acknowledgments

The authors acknowledge the financial support from FAPERJ, CAPES and CNPq; they also thank Dra Maria G.F. Vaz, Marilene M. do Canto-Cavaleiro and Vanessa P. Rodrigues for useful discussions.

supplementary crystallographic information

Comment

Since the discovery of nalidixic acid, the parent compound of the 1,4-dihydro-4-oxoquinoline antibiotics, the molecular structures of oxoquinolines have been extensively modified to improve their pharmacological properties and pharmacokinetic profiles (Van Bambeke et al., 2005). 1,4-Dihydro-4-oxoquinolines have a broad antimicrobial spectrum, are orally and parenterally active and, apart from a few exceptions, are non-toxic compounds. Therefore, they are important agents against microbial pathogens. They have also been considered for the treatment of fungal and viral (Brideau et al., 2002; Souza et al., 2008) infections and for cancer chemotherapy (Chu et al., 1992). Our research group has designed and synthesized new oxoquinoline derivatives, such as ribonucleosides (Canuto et al., 2007) and acyclonucleosides (Lucero et al., 2006). These compounds exhibited interesting activity against HIV-1 and HSV viruses, respectively.

Continuing our interest in the chemistry of oxoquinolinic molecules, we decided to prepare a congener series of new acylhydrazones (Cunha et al., 2003) and test them for antileishmanial activity. These studies showed that the hydrazone group plays an important role in antileishmanial activity (Bernadino et al., 2006). Among these compounds, (E)-1-ethyl-N'-[(pyrid-4'-yl)methylene]-1,4-dihydro-4- oxoquinoline-3-carbohydrazide, was found to exhibit a significant activity against Leishmania amazonensis.

As an extension of our work on the structural characterization of oxoquinolinic derivatives (Canuto et al., 2007; Lucero et al. 2006). the crystal structure of the title compound is reported here. In the title compound (Fig. 1), the dihedral angle between the C1,C6-C9/N1 ring and the C14-C18/N4 pyridine ring is 3.33 (16)°. The plane defined by N1,C10,C11 is inclined to the C1,C6-C9/N1 ring at an angle of 67.87 (16)°. The torsion angles C8—C12—N3—N2, C12—N3—N2—C13 and N3—N2—C13—C14 are 0.79 (14), 1.38 (16) and 1.53 (14)°, respectively. All the bond lengths are within normal ranges (Allen et al., 1987). The molecular structure is stabilized by an intramolecular N—H···O hydrogen bond (Table 1). The crystal structure is stabilized by intermolecular C—H···O hydrogen bonds, forming a one-dimensional structure (Table 1 and Fig. 2).

Experimental

A solution of 1-ethyl-1,4-dihydro-4-oxoquinoline ethyl carboxylate (3.70 mmol) and 3.7 ml of 80% hydrazine monohydrate in 10 ml of dimethylformamide was stirred under reflux for two hours. The reaction mixture was poured into ice, giving rise to a white solid that was collected by filtration, washed with cold ethyl acetate and dried under vacuum, leading to the pure desired 1-ethyl-1,4-dihydro-4-oxoquinoline-3-carbohydrazide, in 90% yield. This carbohydrazide (1.00 mmol) and pyridine-4-carbaldehyde (1.10 mmol) in 5 ml of dimethylformamide and a catalytic amount of 35% HCl were stirred at room temperature. The reaction mixture was poured into ice, leading to a white solid that was collected by filtration, giving (E)-1-ethyl-N'-[(pyrid-4'-yl)methylene]-1,4-dihydro-4-oxoquinoline-3-carbohydrazide in 83% yield after purification.

Refinement

The N-bound H atom was located in a difference map and refined freely [to N—H = 0.92 (2) Å]. The other H atoms were positioned with idealized geometry and refined using a riding model, with C—H = 0.93 Å for aryl, 0.97 Å for methylene, and 0.96 Å for methyl H atoms. The constraints Uiso(H) = 1.2Ueq(C) and 1.5Ueq(C) (methyl C) were applied.

Figures

Fig. 1.
The molecular structure of the title compound showing the atom labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius.
Fig. 2.
The molecular packing, with hydrogen bonds drawn as dashed lines.

Crystal data

C18H16N4O2F(000) = 672
Mr = 320.35Dx = 1.373 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 7914 reflections
a = 7.6460 (12) Åθ = 5.2–25°
b = 19.205 (2) ŵ = 0.09 mm1
c = 10.7050 (9) ÅT = 293 K
β = 99.722 (10)°Prism, yellow
V = 1549.4 (3) Å30.5 × 0.2 × 0.2 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer2001 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.019
graphiteθmax = 25.0°, θmin = 5.2°
Detector resolution: 9 pixels mm-1h = −9→9
[var phi] scans and ω scans winth κ offsetsk = −22→20
7914 measured reflectionsl = −12→8
2586 independent reflections

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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.102H atoms treated by a mixture of independent and constrained refinement
S = 1.07w = 1/[σ2(Fo2) + (0.0352P)2 + 0.5415P] where P = (Fo2 + 2Fc2)/3
2586 reflections(Δ/σ)max < 0.001
222 parametersΔρmax = 0.13 e Å3
0 restraintsΔρmin = −0.14 e Å3

Special details

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.

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

xyzUiso*/Ueq
C10.9168 (2)0.11495 (9)0.16391 (15)0.0361 (4)
C20.8969 (2)0.07582 (10)0.05163 (16)0.0455 (4)
H20.85390.03050.05140.055*
C30.9396 (3)0.10304 (10)−0.05772 (17)0.0516 (5)
H30.92400.0768−0.13180.062*
C41.0065 (3)0.17027 (11)−0.05650 (17)0.0521 (5)
H41.03740.1886−0.13020.063*
C51.0280 (2)0.21026 (10)0.05098 (16)0.0471 (4)
H51.07400.25500.05000.056*
C60.9804 (2)0.18344 (9)0.16269 (15)0.0374 (4)
C70.8708 (2)0.08354 (9)0.27920 (15)0.0371 (4)
C80.8931 (2)0.12883 (8)0.38879 (15)0.0365 (4)
C90.9529 (2)0.19544 (9)0.37882 (15)0.0401 (4)
H90.96380.22350.45050.048*
C101.0520 (3)0.29759 (10)0.27524 (18)0.0538 (5)
H10A1.15000.30260.22910.065*
H10B1.09310.31180.36220.065*
C110.9018 (3)0.34469 (11)0.2170 (2)0.0750 (7)
H11A0.94480.39150.21430.113*
H11B0.80900.34320.26710.113*
H11C0.85630.32930.13240.113*
C120.8472 (2)0.10900 (9)0.51400 (16)0.0416 (4)
C130.6773 (2)−0.04576 (9)0.61567 (16)0.0429 (4)
H130.6722−0.06910.53910.051*
C140.6223 (2)−0.08221 (9)0.72279 (15)0.0388 (4)
C150.5717 (2)−0.15131 (9)0.71190 (17)0.0494 (5)
H150.5690−0.17470.63560.059*
C160.5249 (3)−0.18542 (10)0.81527 (19)0.0544 (5)
H160.4916−0.23190.80570.065*
C170.5729 (3)−0.08884 (11)0.93622 (18)0.0551 (5)
H170.5739−0.06671.01360.066*
C180.6209 (2)−0.05045 (10)0.83932 (17)0.0479 (4)
H180.6521−0.00380.85140.057*
N10.99728 (18)0.22334 (7)0.27329 (12)0.0402 (4)
N20.73182 (18)0.01676 (7)0.62429 (13)0.0419 (4)
N30.7828 (2)0.04327 (8)0.51697 (14)0.0445 (4)
N40.5248 (2)−0.15582 (9)0.92715 (15)0.0541 (4)
O10.81667 (17)0.02200 (6)0.27864 (11)0.0522 (3)
O20.8639 (2)0.14902 (7)0.60464 (12)0.0636 (4)
H3N0.776 (2)0.0178 (10)0.4436 (19)0.057 (6)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0335 (8)0.0403 (10)0.0342 (9)0.0054 (7)0.0048 (7)−0.0024 (7)
C20.0512 (10)0.0443 (10)0.0408 (10)0.0051 (8)0.0074 (8)−0.0066 (8)
C30.0632 (12)0.0569 (12)0.0346 (10)0.0102 (10)0.0078 (8)−0.0070 (8)
C40.0603 (12)0.0623 (13)0.0366 (10)0.0074 (10)0.0163 (8)0.0047 (9)
C50.0523 (11)0.0506 (11)0.0409 (10)0.0003 (9)0.0151 (8)0.0035 (8)
C60.0360 (9)0.0428 (10)0.0343 (9)0.0027 (7)0.0088 (7)−0.0018 (7)
C70.0364 (9)0.0365 (9)0.0388 (9)0.0030 (7)0.0075 (7)−0.0011 (7)
C80.0391 (9)0.0362 (9)0.0354 (9)0.0013 (7)0.0101 (7)−0.0018 (7)
C90.0456 (10)0.0427 (10)0.0342 (9)−0.0017 (8)0.0132 (7)−0.0055 (7)
C100.0727 (13)0.0478 (11)0.0452 (10)−0.0231 (10)0.0227 (9)−0.0063 (9)
C110.114 (2)0.0441 (12)0.0719 (15)−0.0014 (13)0.0312 (14)0.0043 (11)
C120.0491 (10)0.0379 (10)0.0403 (10)0.0021 (8)0.0144 (8)−0.0024 (8)
C130.0520 (10)0.0398 (10)0.0368 (9)−0.0028 (8)0.0071 (8)−0.0011 (7)
C140.0380 (9)0.0378 (9)0.0394 (9)0.0020 (7)0.0029 (7)0.0047 (7)
C150.0611 (12)0.0424 (10)0.0440 (10)−0.0037 (9)0.0066 (9)0.0000 (8)
C160.0643 (13)0.0409 (11)0.0573 (12)−0.0057 (9)0.0084 (10)0.0082 (9)
C170.0720 (13)0.0519 (12)0.0446 (11)0.0025 (10)0.0191 (9)0.0019 (9)
C180.0584 (11)0.0402 (10)0.0457 (10)−0.0006 (8)0.0110 (8)−0.0003 (8)
N10.0474 (8)0.0392 (8)0.0361 (8)−0.0068 (6)0.0128 (6)−0.0033 (6)
N20.0500 (9)0.0395 (9)0.0381 (8)−0.0008 (7)0.0125 (6)0.0029 (6)
N30.0613 (10)0.0397 (9)0.0353 (8)−0.0056 (7)0.0158 (7)0.0001 (7)
N40.0598 (10)0.0525 (10)0.0521 (10)0.0032 (8)0.0149 (8)0.0113 (8)
O10.0732 (9)0.0387 (7)0.0464 (7)−0.0095 (6)0.0147 (6)−0.0056 (5)
O20.1082 (11)0.0441 (8)0.0471 (8)−0.0128 (7)0.0379 (7)−0.0102 (6)

Geometric parameters (Å, °)

C1—C61.403 (2)C10—H10B0.9700
C1—C21.404 (2)C11—H11A0.9600
C1—C71.469 (2)C11—H11B0.9600
C2—C31.371 (2)C11—H11C0.9600
C2—H20.9300C12—O21.227 (2)
C3—C41.388 (3)C12—N31.357 (2)
C3—H30.9300C13—N21.269 (2)
C4—C51.370 (2)C13—C141.465 (2)
C4—H40.9300C13—H130.9300
C5—C61.405 (2)C14—C151.382 (2)
C5—H50.9300C14—C181.390 (2)
C6—N11.398 (2)C15—C161.384 (3)
C7—O11.2518 (19)C15—H150.9300
C7—C81.447 (2)C16—N41.326 (2)
C8—C91.369 (2)C16—H160.9300
C8—C121.491 (2)C17—N41.337 (2)
C9—N11.344 (2)C17—C181.372 (3)
C9—H90.9300C17—H170.9300
C10—N11.485 (2)C18—H180.9300
C10—C111.511 (3)N2—N31.3719 (19)
C10—H10A0.9700N3—H3N0.92 (2)
C6—C1—C2118.79 (15)C10—C11—H11B109.5
C6—C1—C7121.70 (14)H11A—C11—H11B109.5
C2—C1—C7119.52 (15)C10—C11—H11C109.5
C3—C2—C1121.32 (17)H11A—C11—H11C109.5
C3—C2—H2119.3H11B—C11—H11C109.5
C1—C2—H2119.3O2—C12—N3123.61 (16)
C2—C3—C4119.16 (17)O2—C12—C8122.81 (15)
C2—C3—H3120.4N3—C12—C8113.58 (14)
C4—C3—H3120.4N2—C13—C14121.97 (15)
C5—C4—C3121.40 (17)N2—C13—H13119.0
C5—C4—H4119.3C14—C13—H13119.0
C3—C4—H4119.3C15—C14—C18116.92 (16)
C4—C5—C6119.85 (17)C15—C14—C13120.43 (16)
C4—C5—H5120.1C18—C14—C13122.65 (16)
C6—C5—H5120.1C14—C15—C16119.58 (17)
N1—C6—C1119.25 (14)C14—C15—H15120.2
N1—C6—C5121.31 (16)C16—C15—H15120.2
C1—C6—C5119.44 (15)N4—C16—C15123.99 (18)
O1—C7—C8124.40 (15)N4—C16—H16118.0
O1—C7—C1120.64 (14)C15—C16—H16118.0
C8—C7—C1114.96 (14)N4—C17—C18124.58 (18)
C9—C8—C7119.59 (14)N4—C17—H17117.7
C9—C8—C12116.19 (14)C18—C17—H17117.7
C7—C8—C12124.17 (15)C17—C18—C14119.08 (18)
N1—C9—C8124.96 (15)C17—C18—H18120.5
N1—C9—H9117.5C14—C18—H18120.5
C8—C9—H9117.5C9—N1—C6119.53 (14)
N1—C10—C11112.13 (16)C9—N1—C10118.75 (14)
N1—C10—H10A109.2C6—N1—C10121.59 (13)
C11—C10—H10A109.2C13—N2—N3115.25 (14)
N1—C10—H10B109.2C12—N3—N2121.35 (15)
C11—C10—H10B109.2C12—N3—H3N116.4 (12)
H10A—C10—H10B107.9N2—N3—H3N122.2 (12)
C10—C11—H11A109.5C16—N4—C17115.84 (16)
C6—C1—C2—C30.6 (2)C6—C1—C2—H2−179.4
C7—C1—C2—C3−179.53 (16)C7—C1—C2—H20.5
C1—C2—C3—C41.0 (3)C1—C2—C3—H3−179.0
C2—C3—C4—C5−1.1 (3)H2—C2—C3—H31.0
C3—C4—C5—C6−0.6 (3)H2—C2—C3—C4−179.0
C2—C1—C6—N1178.70 (14)C2—C3—C4—H4178.9
C7—C1—C6—N1−1.2 (2)H3—C3—C4—H4−1.1
C2—C1—C6—C5−2.2 (2)H3—C3—C4—C5178.9
C7—C1—C6—C5177.95 (14)C3—C4—C5—H5179.4
C4—C5—C6—N1−178.71 (16)H4—C4—C5—H5−0.6
C4—C5—C6—C12.2 (3)H4—C4—C5—C6179.4
C6—C1—C7—O1−178.98 (15)H5—C5—C6—C1−177.8
C2—C1—C7—O11.1 (2)H5—C5—C6—N11.3
C6—C1—C7—C81.0 (2)C7—C8—C9—H9178.8
C2—C1—C7—C8−178.88 (14)C12—C8—C9—H91.4
O1—C7—C8—C9−179.87 (16)H9—C9—N1—C10−2.9
C1—C7—C8—C90.1 (2)H9—C9—N1—C6−178.9
O1—C7—C8—C12−2.7 (3)H10A—C10—C11—H11A−54.6
C1—C7—C8—C12177.27 (14)H10A—C10—C11—H11B−174.6
C7—C8—C9—N1−1.2 (3)H10A—C10—C11—H11C65.4
C12—C8—C9—N1−178.55 (15)H10B—C10—C11—H11A63.1
C9—C8—C12—O2−1.1 (3)H10B—C10—C11—H11B−56.9
C7—C8—C12—O2−178.36 (17)H10B—C10—C11—H11C−176.9
C9—C8—C12—N3177.80 (15)N1—C10—C11—H11A−175.7
C7—C8—C12—N30.6 (2)N1—C10—C11—H11B64.3
N2—C13—C14—C15−176.91 (16)N1—C10—C11—H11C−55.7
N2—C13—C14—C181.9 (3)H10A—C10—N1—C6−43.9
C18—C14—C15—C16−0.8 (3)H10A—C10—N1—C9140.2
C13—C14—C15—C16178.15 (16)H10B—C10—N1—C6−161.6
C14—C15—C16—N40.2 (3)H10B—C10—N1—C922.5
N4—C17—C18—C14−0.6 (3)C8—C12—N3—H3N1.0 (13)
C15—C14—C18—C170.9 (3)H13—C13—C14—C153.1
C13—C14—C18—C17−177.93 (17)H13—C13—C14—C18−178.1
C8—C9—N1—C61.1 (2)H13—C13—N2—N3−1.5
C8—C9—N1—C10177.08 (16)C13—C14—C15—H15−1.8
C1—C6—N1—C90.2 (2)C18—C14—C15—H15179.2
C5—C6—N1—C9−178.95 (15)C13—C14—C18—H182.1
C1—C6—N1—C10−175.74 (15)C15—C14—C18—H18−179.1
C5—C6—N1—C105.1 (2)C14—C15—C16—H16−179.8
C11—C10—N1—C9−98.68 (19)H15—C15—C16—H160.2
C11—C10—N1—C677.3 (2)H15—C15—C16—N4−179.8
C14—C13—N2—N3178.47 (14)H16—C16—N4—C17−179.7
O2—C12—N3—N2−0.3 (3)H17—C17—C18—C14179.4
C8—C12—N3—N2−179.21 (14)H17—C17—C18—H18−0.6
C13—N2—N3—C12−178.62 (16)N4—C17—C18—H18179.4
C15—C16—N4—C170.3 (3)H17—C17—N4—C16180.0
C18—C17—N4—C160.0 (3)C13—N2—N3—H3N1.2 (14)
C6—C1—C2—H2−179.43 (1)O2—C12—N3—H3N179.9 (13)
C7—C1—C2—H20.46 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N3—H3N···O10.92 (2)1.85 (2)2.639 (2)143.1 (17)
C10—H10A···O2i0.972.463.398 (2)163

Symmetry codes: (i) x+1/2, −y+1/2, z−1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WN2340).

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