6-Amino-3-methyl-4-(3-nitro­phen­yl)-1-phenyl-1H,4H-pyrano[2,3-c]pyrazole-5-carbonitrile

Ming-Shu Wu; Du-Lin Kong; Xiang-Zhu Zhang

doi:10.1107/S1600536811017387

. 2011 May 20;67(Pt 6):o1454–o1455. doi: 10.1107/S1600536811017387

6-Amino-3-methyl-4-(3-nitrophenyl)-1-phenyl-1H,4H-pyrano[2,3-c]pyrazole-5-carbonitrile

Ming-Shu Wu ^a,^b,^*, Du-Lin Kong ^b, Xiang-Zhu Zhang ^a

PMCID: PMC3120331 PMID: 21754828

Abstract

The title compound, C₂₀H₁₅N₅O₃, was synthesized by the one-pot reaction of a four-component reaction protocol in aqueous medium. The pyrano[2,3-c]pyrazole system is essentially planar, with a maximum deviation of 0.026 (2) Å. The 3-nitrophenyl and phenyl rings make dihedral angles of 81.11 (5) and 13.36 (1)°, respectively, with the mean plane of the pyrano[2,3-c]pyrazole ring. The crystal structure is stabilized by N—H⋯N hydrogen bonds, which form infinite chain propagating along the c axis and by N—H⋯O hydrogen bonds, which form infinite chains propagating along the a axis. There are also N—O⋯N—C dipole–dipole interactions along the a axis with an O⋯N distance of 3.061 (3) Å, which is shorter than that of the N—H⋯O hydrogen bond [3.196 (3) Å].

Related literature

For the antimicrobial, insecticidal and anti-inflammatory activity of pyranopyrazole derivatives, see: El-Tamany et al. (1999 ▶); Ismail et al. (2003 ▶); Zaki et al. (2006 ▶) and for their applications as pharmaceutical ingredients and biodegradable agrochemicals, see: Junek & Aigner (1973 ▶); Sharanin et al. (1983 ▶); Vasuki & Kumaravel (2008 ▶); Wamhoff et al. (1993 ▶). For the Chk1 kinase inhibitor, see: Foloppe et al. (2006 ▶). For the use of multi-component reaction (MCR) protocols in water in the development of libraries of medicinal scaffolds, see: Chanda & Fokin (2009 ▶); Tejedor & Garcia-Tellado (2007 ▶).

Experimental

Crystal data

C₂₀H₁₅N₅O₃
M _r = 373.37
Monoclinic,
a = 9.5089 (8) Å
b = 13.9137 (11) Å
c = 13.3747 (12) Å
β = 96.263 (1)°
V = 1759.0 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 298 K
0.50 × 0.48 × 0.47 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▶) T _min = 0.952, T _max = 0.955
8659 measured reflections
3087 independent reflections
1961 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.121
S = 1.07
3087 reflections
255 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2002 ▶); 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811017387/zk2006sup1.cif

e-67-o1454-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811017387/zk2006Isup2.hkl

e-67-o1454-Isup2.hkl^{(151.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811017387/zk2006Isup3.cml

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
N3—H3A⋯O2ⁱ	0.86	2.63	3.196 (3)	124
N3—H3B⋯N4ⁱⁱ	0.86	2.22	3.067 (3)	169
C19—H19⋯O2ⁱⁱⁱ	0.93	2.54	3.294 (4)	139

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

supplementary crystallographic information

Comment

Multi-component reaction (MCR) protocols in water will be one of the most suitable strategies, which will meet the requirements of green chemistry as well as for developing libraries of medicinal scaffolds (Chanda et al., 2009; Tejedor et al., 2007). pyranopyrazoles are an important class of heterocyclic compounds. They found applications as pharmaceutical ingredients and biodegradable agrochemicals (Junek et al., 1973; Wamhoff et al., 1993; Sharanin et al., 1983; Vasuki et al., 2008). In order to further study the structure-activity relationship of pyranopyrazoles, we performed the synthesis of the title compound through an efficient and eco-friendly four-component one-pot reaction protocol in aqueous medium in the presence of catalytic amount dodecyltrimethylammonium bromide and present the crystal structure of the title compound in the hope that its structural features will appear interesting and helpful its practical applications. In the title molecule (Fig. 1), The pyranopyrazole ring essentially planar with a maximum deviation of 0.026 (0) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angles formed by the mean plane of the pyranopyrazole fragment with the 3-nitrophenyl ring and phenyl ring is 81.11 (5)° and 13.36 (1)° , respectively. In the crystal the molecular packing (Fig. 2) is stabilized by Infinite chains via N-H···N hydrogen bonds propagate along c-axis, infinite chains via N-H···O hydrogen bonds propagate along a-axis and along a-axis there exists N-O···N-C dipole-dipole interactions with O···N distance of 3.061 Å which shorter than that of N-H···O (3.196 Å) hydrogen bond.

Experimental

To a stirred aqueous mixture of phenylhydrazine ( 0.216g, 2 mmol) and ethyl acetoacetate ( 0.260g, 2 mmol), 3-nitrobenzaldehyde ( 0.302g, 2 mmol), malonitrile ( 0.132g, 2 mmol) and piperidine (5 mol %) were added successively at 363 K in the presence of catalytic amount dodecyltrimethylammonium bromide with vigorous stirring for 10 min. The precipitated solid was filtered, washed with water and then with a mixture of ethyl acetate/hexane (20:80). The product obtained was purified by flash chromatograghy. Single crystals of the title compound suitable for single-crystal X-ray analysis were obtained by recrystallization from ethanol.