6,7-Dihydro-4-(4-methoxy­phen­yl)-3-methyl-6-oxo-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile

Xin-Ying Zhang; Xiao-Yan Li; Xia Wang; Dong-Fang Li; Xue-Sen Fan

doi:10.1107/S1600536808027852

. 2008 Sep 6;64(Pt 10):o1888. doi: 10.1107/S1600536808027852

6,7-Dihydro-4-(4-methoxyphenyl)-3-methyl-6-oxo-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile

Xin-Ying Zhang ^a,^*, Xiao-Yan Li ^a, Xia Wang ^a, Dong-Fang Li ^a, Xue-Sen Fan ^a

PMCID: PMC2959259 PMID: 21201100

Abstract

In the title compound, C₂₁H₁₆N₄O₂, the dihedral angle between the methoxy-substituted benzene ring and the ring system formed by the pyridinone ring and the pyrazole ring is 57.4 (1)°, and that between the unsubstituted phenyl ring and the ring system is 135.6 (1)°. In the crystal structure, molecules are linked together via intermolecular N—H⋯O hydrogen bonds.

Related literature

For the biological and pharmacological activities of pyrazolo[3,4-b]pyridine derivatives, see Falcó et al. (2005 ▶); Ludwig et al. (2004 ▶). For a related structure, see Quiroga et al. (1999 ▶).

Experimental

Crystal data

C₂₁H₁₆N₄O₂
M _r = 356.38
Triclinic,
a = 7.0621 (11) Å
b = 11.0272 (17) Å
c = 12.1743 (19) Å
α = 68.467 (2)°
β = 78.949 (2)°
γ = 87.471 (2)°
V = 865.2 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 295 (2) K
0.43 × 0.30 × 0.11 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: none
6198 measured reflections
3136 independent reflections
2236 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.114
S = 1.02
3136 reflections
246 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT (Bruker, 1997 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808027852/xu2451sup1.cif

e-64-o1888-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808027852/xu2451Isup2.hkl

e-64-o1888-Isup2.hkl^{(153.8KB, 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
N1—H1⋯O1ⁱ	0.86	2.06	2.8523 (18)	153

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 20772025) and the Program for Science and Technology Innovation Talents in Universities of Henan Province (No. 2008HASTIT006).

supplementary crystallographic information

Comment

Pyrazolo[3,4-b]pyridine derivatives have been found of interests for their biological and pharmacological activities, such as antiviral (Ludwig et al., 2004). Moreover, pyrazolo[3,4-b]pyridin-6-ones as a subunit of pyrazolo[3,4-b]pyridine acted as potential hypnotic drugs in many cases (Falcó et al., 2005). Due to their importance, many methods have been reported for the construction of pyrazolo[3,4-b]pyridine derivatives including pyrazolo[3,4-b]pyridin-6-ones (Quiroga et al., 1999; Falcó et al., 2005). Herein, we report the crystal structure of the title compound, one of pyrazolo[3,4-b]pyridin-6-one derivatives.

In the title compound there are four rings including two phenyl rings, one pyridinone ring and one pyrazole ring. The pyridinone ring and the pyrazole ring is almost co-planar and formed a ring system. The dihedral angle between this ring system and the methoxy-substituted phenyl ring is 57.4 (1)°, which is probably due to the repulsion of the cyano group on the pyridinone ring and the hydrogen atoms on the ortho-positions of the phenyl ring connected with the pyridinone ring, and the repulsion between these hydrogen atoms and the methyl group on the pyrazole ring. The dihedral angle between the non-substituted phenyl ring and the ring system is 135.6 (1)°.

In the crystal structure the molecules are connected via intermolecular N—H···O hydrogen bonding (Table 1).

Experimental

To 1 ml of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]) were added 4-methoxybenzaldehyde (1 mmol, II) and ethyl cyanoacetate (1 mmol). The mixture was stirred at 80 °C until the disappearance of II. Then, 5-amino-3-methyl-1-phenylpyrazole (1 mmol) and FeCl₃.6H₂O (0.2 mmol) was added and the mixture was continued to be stirred at the same temperature to complete the reaction (monitored by TLC). The reaction time was 10 h totally. Upon completion, the mixture was cooled to room temperature and 2 ml of 50% ethanol in water was added. The product was collected by suction and rinsed with water and cool ethanol in a yield of 90% as white solid. Single crystals of the title compound were obtained by slow evaporation of the solvent from an ethyl acetate-ethanol (1:1 v/v) solution.