Ethyl 6-methyl-2-p-tolyl­pyrazolo[1,5-a]pyridine-5-carboxyl­ate

Jiong Jia; Yan-qing Ge; Gui-long Zhao; Jian-wu Wang

doi:10.1107/S1600536809035314

. 2009 Sep 9;65(Pt 10):o2372. doi: 10.1107/S1600536809035314

Ethyl 6-methyl-2-p-tolylpyrazolo[1,5-a]pyridine-5-carboxylate

Jiong Jia ^a, Yan-qing Ge ^a, Gui-long Zhao ^a, Jian-wu Wang ^a,^*

PMCID: PMC2970404 PMID: 21577837

Abstract

In the title molecule, C₁₈H₁₈N₂O₂, the bicyclic ring system and the benzene ring form a dihedral angle of 13.45 (3)°. In the crystal structure, weak intermolecular C—H⋯O hydrogen bonds link molecules into chains propagated along [201].

Related literature

For novel pyrazolo[1,5-a]pyridine compounds, see: Ge et al. (2009 ▶). For a related structure, see: Shao et al. (2009 ▶).

Experimental

Crystal data

C₁₈H₁₈N₂O₂
M _r = 294.34
Monoclinic,
a = 6.8352 (3) Å
b = 30.3999 (11) Å
c = 7.5409 (3) Å
β = 97.375 (2)°
V = 1553.96 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 K
0.43 × 0.32 × 0.21 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.965, T _max = 0.983
18651 measured reflections
3181 independent reflections
2166 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.148
S = 1.07
3181 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.22 e Å⁻³

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

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809035314/cv2611sup1.cif

e-65-o2372-sup1.cif^{(19.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809035314/cv2611Isup2.hkl

e-65-o2372-Isup2.hkl^{(156.1KB, 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
C9—H9A⋯O3ⁱ	0.93	2.42	3.339 (3)	170

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The pyrazolo[1,5-a]pyridine derivatives have been of interest for their pharmacological and biological activities. Considerable efforts of our group have been devoted to the development of novel pyrazolo[1,5-a]pyridine compounds(Ge et al., 2009). In continuation of this work, we report here the crystal structure of the title compound, (I) (Fig. 1).

In (I), all bond lengths are normal and in a good agreement with those reported previously (Shao et al., 2009). Atoms O2/O3/C15/C16/C17/C18 lie in 1H-pyrazolo[1,5-a]pyridine (C8—C14/N1/N2) plane with the maximum deviation of 0.065 (3) Å for O2. The 1H-pyrazolo[1,5-a]pyridine plane forms dihedral angle of 13.45 (3)° with the benzene ring (C2—C7).

In the crystal structure, weak intermolecular C–H···O hydrogen bond (Table 1) link the molecules into chains propagated in direction [201].

Experimental

To a 50-ml round-bottomed flask were added 3-p-tolyl-1H-pyrazole-5-carbaldehyde(6.0 mmol), ethyl 4-bromo-3-methylbut-2-enoate (7.2 mmol), potassium carbonate (1.60 g, 12.5 mmol) and DMF (10 mL). The mixture was stirred at rt for 8 h and then filtered. The filtrate was poured into water (100 ml) and extracted with CH₂Cl₂ (3 x 30 ml). The combined extracts were washed with water (2 x 50 ml), dried over anhydrous MgSO4 and filtered, and the solvent was removed by rotary evaporation. The crude product was purified by column chromatography (yield 75%). Crystals of (I) suitable for X-ray diffraction were obtained by slow cooling of the refluxed solution of the product in ethyl acetate at room temperature for 2 d.