1-[5-(2-Chloro­phen­yl)-5-hy­droxy-3-methyl-4,5-dihydro-1H-pyrazol-1-yl]­ethanone

Sheng-Hai Guo; Ji-Liang Wang; Dong-Qiang Guo; Xin-Ying Zhang

doi:10.1107/S1600536812007283

. 2012 Feb 24;68(Pt 3):o839. doi: 10.1107/S1600536812007283

1-[5-(2-Chlorophenyl)-5-hydroxy-3-methyl-4,5-dihydro-1H-pyrazol-1-yl]ethanone

Sheng-Hai Guo ^a, Ji-Liang Wang ^a, Dong-Qiang Guo ^a, Xin-Ying Zhang ^a,^*

PMCID: PMC3297897 PMID: 22412700

Abstract

The title compound, C₁₂H₁₃ClN₂O₂, crystallizes with two independent but very similar molecules (A and B) in the asymmetric unit. The pyrazole ring in each molecule has an envelope conformation. The dihedral angle between the pyrazole ring mean plane and the benzene ring is 86.07 (14)° in A and 85.99 (14)° in B. In the crystal, the A and B molecules are linked via a pair of O—H⋯O hydrogen bonds, forming dimers. These dimers are further linked via C—H⋯O interactions to form –A–B–A–B– chains propagating along the c-axis direction.

Related literature

For the bioactivities of 5-hydroxypyrazolines, see: Sauzem et al. (2008 ▶); Zhao et al. (2009 ▶); Idrees et al. (2009 ▶). For the crystal structures of related 5-hydroxypyrazolines, see: Kargar, Kia, Froozandeh et al. (2011 ▶); Kargar, Kia, Moghadamm et al. (2011 ▶).

Experimental

Crystal data

C₁₂H₁₃ClN₂O₂
M _r = 252.70
Monoclinic,
a = 10.320 (3) Å
b = 14.916 (4) Å
c = 16.346 (4) Å
β = 95.158 (3)°
V = 2506.0 (12) Å³
Z = 8
Mo Kα radiation
μ = 0.30 mm⁻¹
T = 296 K
0.39 × 0.25 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.893, T _max = 0.957
16979 measured reflections
4663 independent reflections
3077 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.159
S = 1.02
4663 reflections
313 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.35 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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 datablock(s) I, global. DOI: 10.1107/S1600536812007283/su2378sup1.cif

e-68-0o839-sup1.cif^{(24.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812007283/su2378Isup2.hkl

e-68-0o839-Isup2.hkl^{(228.4KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812007283/su2378Isup3.cdx

Supplementary material file. DOI: 10.1107/S1600536812007283/su2378Isup4.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
O1—–H1⋯..O4ⁱ	0.82	1.97	2.748 (3)	159
O3—–H3A⋯..O2ⁱⁱ	0.82	2.03	2.792 (3)	155
C8—–H8B⋯..O3ⁱⁱⁱ	0.97	2.53	3.410 (3)	151
C20—–H20B⋯..O1^iv	0.97	2.50	3.354 (3)	147

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

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant No. 21172057).

supplementary crystallographic information

Comment

5-Hydroxypyrazolines have drawn much attention due to their interesting biological properties such as anti-inflammatory, antibiotic, and hypolipidemic activities (Sauzem et al., 2008; Zhao et al., 2009; Idrees et al., 2009). Crystal structures of some 5-hydroxypyrazoline derivatives have been reported (Kargar, Kia, Froozandeh et al., 2011; Kargar, Kia, Moghadamm et al., 2011). Herein, we report on the crystal structure of the new title 5-hydroxypyrazoline derivative.

The title compound crystallizes with two independent but very similar molecules (A and B) in the asymmetric unit (Fig. 1). All the bond lengths and bond angles are within normal ranges. The five-membered pyrazole rings have envelope conformations with atom C7 as the flap in molecule A, and atom C19 as the flap in molecule B. The dihedral angle between the pyrazole ring mean plane and the phenyl ring is 86.07 (14) ° in A and 85.99 (14) ° in B.

In the crystal, the A and B molecules are linked via a pair of O—H···O hydrogen bonds forming dimers. These dimers are further linked via C-H···O interactions to form -A-B-A-B- chains propagating along the c axis direction (Table 1 and Fig. 2).

Experimental

1-(2-chlorophenyl)butane-1,3-dione (1.0 mmol), acetohydrazide (1.0 mmol), and a drop of concentrated H₂SO₄ were mixed and ground for 10 min in a mortar. Upon completion of the reaction, monitored by TLC, ethyl acetate and water were added to the reaction mixture. Then, the organic layer was washed with Na₂CO₃ solution and water, and dried over anhydrous Na₂SO₄. Ethyl acetate was removed under reduced pressure and the residue was purified by chromatography on silica-gel to provide the title product as a white solid. Colourless block-like crystals of the title compound, suitable for X-ray diffraction analysis, were obtained by slow evaporation of the solvent from a dichloromethane solution at room temperature.