N-[(E)-Quinoxalin-2-ylmethyl­idene]-1H-indazol-5-amine

P Leeju; V Arun; Manju Sebastian; G Varsha; Digna Varghese; K K M Yusuff

doi:10.1107/S1600536809027822

. 2009 Jul 25;65(Pt 8):o1981. doi: 10.1107/S1600536809027822

N-[(E)-Quinoxalin-2-ylmethylidene]-1H-indazol-5-amine

P Leeju ^a, V Arun ^a, Manju Sebastian ^a, G Varsha ^a, Digna Varghese ^a, K K M Yusuff ^a,^*

PMCID: PMC2977485 PMID: 21583657

Abstract

In the title molecule, C₁₆H₁₁N₅, the mean planes of the quinoxaline and indazole fragments form a dihedral angle of 10.62 (5)°. In the crystal, weak intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag chains extending in the [001] direction. The crystal packing also exhibits π–π interactions [centroid–centroid distances of 3.7080 (2) and 3.8220 (5) Å], which form stacks of the molecules parallel to the a axis.

Related literature

For related structures, see: Varghese et al. (2009 ▶); Varsha et al. (2009 ▶).

Experimental

Crystal data

C₁₆H₁₁N₅
M _r = 273.30
Monoclinic,
a = 7.7015 (6) Å
b = 8.0330 (6) Å
c = 20.6034 (16) Å
β = 96.882 (2)°
V = 1265.47 (17) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.45 × 0.27 × 0.08 mm

Data collection

Bruker Kappa APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.960, T _max = 0.993
16012 measured reflections
3597 independent reflections
2502 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.143
S = 1.03
3597 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; 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: publCIF (Westrip, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global, schiflm. DOI: 10.1107/S1600536809027822/cv2578sup1.cif

e-65-o1981-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809027822/cv2578Isup2.hkl

e-65-o1981-Isup2.hkl^{(172.8KB, 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
N4—H4⋯N1ⁱⁱⁱ	0.86	2.31	3.1050 (15)	153

Open in a new tab

Symmetry code: (iii) Inline graphic .

Acknowledgments

The X-ray data were collected on the diffractometer facilities at the Indian Institute of Technology, Madras, provided by the Department of Science and Technology. MS thanks the Kerala State Council for Science, Technology and the Environment, Trivandrum, Kerala, for support. DV acknowledges the Council of Scientific and Industrial Research (CSIR), India, for financial assistance.

supplementary crystallographic information

Comment

In view of synthesizing new quinoxaline based Schiff bases, we have undertaken the synthesis of the title compound, (1), and report here its crystal structure. In (1), the quinoxaline ring and indazole ring are each approximately planar, with the maximum deviations of 0.0254 (4) and 0.0213 (4) Å from the least square planes, respectively. A perspective drawing is depicted in figure 1 with the atomic numbering scheme. The compound is non-planar due to the twisting of rings with respect to azomethine group. Bond lengths and angles are in normal ranges and comparable to those in related structures (Varghese et al., 2009; Varsha et al., 2009). In the crystal structure, molecules are held together by π–π stacking interactions and N—H···N intermolecular hydrogen bonding.

Experimental

A hot solution of 5-aminoindazole (1 mmol) in ethanol (20 ml) was added slowly to a hot solution of quinoxaline-2-carboxaldehyde (1 mmol) in the same solvent (40 ml).The resulting mixture on cooling yielded the crude product of (1). Pale green crystals suitable for single-crystal XRD are obtained by slow evaporation of ethanolic solution of (1).