5-Chloro-3,6-dimethyl-1-phenyl-1H,4H-pyrano[2,3-c]pyrazol-4-one

Abdullah M Asiri; Hassan M Faidallah; Khalid A Alamry; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812028528

. 2012 Jun 30;68(Pt 7):o2257. doi: 10.1107/S1600536812028528

5-Chloro-3,6-dimethyl-1-phenyl-1H,4H-pyrano[2,3-c]pyrazol-4-one

Abdullah M Asiri ^a,^b,^‡, Hassan M Faidallah ^b, Khalid A Alamry ^a,^b, Seik Weng Ng ^c, Edward R T Tiekink ^c,^*

PMCID: PMC3394042 PMID: 22798907

Abstract

In the title compound, C₁₄H₁₁ClN₂O₂, two independent molecules (A and B) comprise the asymmetric unit with the main difference between them being the relative orientation of the pendent phenyl ring with respect to the fused-ring system [dihedral angles = 8.32 (8)° (A) and 28.32 (8)° (B)]. In the crystal, the A molecules are connected into a linear supramolecular chain along the a axis via C—H⋯O interactions and linked to this via C—H⋯Cl interactions are the B molecules. The chains are connected into layers in the ab plane by π–π interactions between pyrazole (A) and pyran (B) rings, and between pyrazole (B) and pyran (A) rings [centroid–centroid distances = 3.5442 (11) and 3.4022 (10) Å, respectively].

Related literature

For the analgesic and anti-inflammatory activity of pyrano[2,3-c]pyrazole derivatives, see: Kuo et al. (1984 ▶). For the synthesis, see: Gelin et al. (1983 ▶). For the structure of the derivative without a chloro substituent, see: Asiri et al. (2012 ▶).

Experimental

Crystal data

C₁₄H₁₁ClN₂O₂
M _r = 274.70
Orthorhombic,
a = 11.8864 (4) Å
b = 13.6276 (5) Å
c = 31.0273 (10) Å
V = 5025.9 (3) Å³
Z = 16
Mo Kα radiation
μ = 0.30 mm⁻¹
T = 100 K
0.40 × 0.20 × 0.20 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.817, T _max = 1.000
17994 measured reflections
5796 independent reflections
4522 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.117
S = 1.03
5796 reflections
347 parameters
H-atom parameters constrained
Δρ_max = 0.56 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812028528/su2466sup1.cif

e-68-o2257-sup1.cif^{(25.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812028528/su2466Isup2.hkl

e-68-o2257-Isup2.hkl^{(283.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812028528/su2466Isup3.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
C12—H12⋯O2ⁱ	0.95	2.32	3.203 (2)	154
C14—H14⋯Cl2ⁱ	0.95	2.74	3.448 (2)	132

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are grateful to King Abdulaziz University for providing research facilities. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

In connection with reports that pyrano[2,3-c]pyrazole derivatives possess analgesic and anti-inflammatory activities (Kuo et al., 1984), the title compound (I) was synthesized, following a literature procedure (Gelin et al., 1983), and its crystal and molecular structure are reported on herein.

In (I), Fig. 1, two independent molecules comprise the asymmetric unit. As seen from the overlay diagram, Fig. 2, these are virtually super-imposable. The primary difference between the molecules relates to the relative orientation of the pendent phenyl ring with respect to the fused-ring system [r.m.s. deviations = 0.024 and 0.021 Å, respectively] as seen in the dihedral angles of 8.32 (8) and 28.32 (8)°, respectively. In the structure of the derivative without a chloro substituent, the molecule is planar with the r.m.s. of all non-hydrogen atoms being 0.038 Å (Asiri et al., 2012).

In the crystal, the Cl1-containing molecules are connected into a linear supramolecular chain along the a axis via C—H···O interactions and linked to this via C—H···Cl interactions are the Cl2-containing molecules, Fig. 3 and Table 1. Chains are connected into layers in the ab plane by π—π interactions with the closest of these occurring between the five-membered and six-membered in an alternating sequence of the independent molecules [ring centroid(N1-pyrazole)···(O3-pyrano)ⁱ = 3.5442 (11) Å, angle of inclination = 2.29 (11)° for i: -x+1, -y, -z+1; ring centroid(N3-pyrazole)···(O1-pyrano)ⁱⁱ = 3.4022 (10) Å, angle of inclination = 5.38 (8)° for ii: x+1/2, -y+1/2, -z+1]. The layers stack along the c axis with no specific intermolecular interactions between them, Fig. 4.

Experimental

To a solution of 4-(acetoacetyl)-3-methyl-1-phenyl-2-pyrazolin-5-one (0.01 M), made following a literature procedure (Gelin et al., 1983), in dry methylene chloride (20 ml) was added drop-wise sulfuryl chloride (1.35 g, 0.01 M). The mixture was allowed to stand at room temperature for 2 h and then poured into a 10% aqueous K₂CO₃ solution (50 ml) with stirring for 5 min. The aqueous layer was acidified with 10% HCl and extracted with chloroform. The combined organic extracts were washed with water and dried (Na₂SO₄). Removal of the solvent gave 4-(aceto-chloroacetyl)-3-methyl-1-phenyl-2-pyrazolin-5-one. Concentrated sulfuric acid (1 ml) was then added drop-wise. After 4 h at room temperature, the mixture was poured into ice-water (200 ml). The precipitate was extracted with chloroform. The chloroform layer was washed with 5% aqueous K₂CO₃ solution, dried and evaporated to give the title compound which was recrystallized from ethanol. M.p: 413–415 K cf. Lit. M.p. 413 K (Gelin et al., 1983). Yield: 68%.