5-Pentyl-4-phenyl­sulfonyl-1H-pyrazol-3-ol

Tara Shahani; Hoong-Kun Fun; R Venkat Ragavan; V Vijayakumar; S Sarveswari

doi:10.1107/S1600536810019458

. 2010 May 29;66(Pt 6):o1482–o1483. doi: 10.1107/S1600536810019458

5-Pentyl-4-phenylsulfonyl-1H-pyrazol-3-ol

Tara Shahani ^a, Hoong-Kun Fun ^a,^*,^‡, R Venkat Ragavan ^b, V Vijayakumar ^b, S Sarveswari ^b

PMCID: PMC2979633 PMID: 21579547

Abstract

In the title compound, C₁₄H₁₈N₂O₃S, the 1H-pyrazole ring is approximately planar, with a maximum deviation of 0.005 (1) Å. The dihedral angle formed between the 1H-pyrazole and phenyl rings is 79.09 (5)°. Pairs of intermolecular N—H⋯O and O⋯H⋯N hydrogen bonds form dimers between neighboring molecules, generating R ₂ ²(10) ring motifs. These dimers are further linked by intermolecular N—H⋯O and O—H⋯N hydrogen bonds into two-dimensional arrays parallel to the ac plane. The crystal structure is also stabilized by C—H⋯π interactions.

Related literature

For background to the biological activity of 3-ethyl-4-methyl-1H-pyrazol-5-ol, see: Brogden (1986 ▶); Gursoy et al. (2000 ▶); Ragavan et al. (2009 ▶, 2010 ▶); Watanabe et al. (1984 ▶); Kawai et al. (1997 ▶); Wu et al. (2002 ▶). For related structures, see: Shahani et al. (2009 ▶, 2010a ▶,b ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For reference bond-length data, see: Allen et al. (1987 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₄H₁₈N₂O₃S
M _r = 294.36
Monoclinic,
a = 10.3425 (3) Å
b = 11.2963 (3) Å
c = 12.8911 (3) Å
β = 107.419 (1)°
V = 1437.02 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 100 K
0.48 × 0.33 × 0.11 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.896, T _max = 0.976
28969 measured reflections
7810 independent reflections
6336 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.122
S = 1.14
7810 reflections
253 parameters
All H-atom parameters refined
Δρ_max = 0.73 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810019458/wn2386sup1.cif

e-66-o1482-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810019458/wn2386Isup2.hkl

e-66-o1482-Isup2.hkl^{(382.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the 1H-pyrazole ring (C7–C9/N1/N2).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H1O3⋯N1ⁱ	0.945 (19)	1.79 (2)	2.7287 (10)	171.5 (17)
N2—H1N2⋯O2ⁱⁱ	0.880 (19)	1.959 (19)	2.7162 (10)	143.4 (17)
C12—H12A⋯Cg1ⁱⁱⁱ	1.005 (16)	2.952 (16)	3.5692 (10)	120.5 (11)

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

Acknowledgments

TSH and HKF thank Universiti Sains Malaysia (USM) for the Research University Golden Goose Grant (1001/PFIZIK/811012). VV is grateful to the DST-India for funding through the Young Scientist Scheme (Fast Track Proposal).

supplementary crystallographic information

Comment

Pyrazolone derivatives have a broad spectrum of biological activities, being used as analgesic, antipyretic and anti-inflammatory therapeutical drugs (Brogden, 1986; Gursoy et al., 2000). A class of new compounds with the pyrazolone unit has been synthesized and reported to possess antibacterial and antifungal activities (Ragavan et al., 2009, 2010). A new pyrazolone derivative, edaravone (3-methyl-1-phenyl-2-pyrazoline-5-one), is being used as a drug in clinical practice for brain ischemia (Watanabe et al., 1984; Kawai et al., 1997) and the same has been found to be effective against myocardial ischemia (Wu et al., 2002).

In the crystal structure (Fig. 1), the 1H-pyrazole ring (C1–C2/N1/N2) is approximately planar, with a maximum deviation of 0.005 (1) Å at atoms C9 and N2. The dihedral angle formed between the 1H-pyrazole and phenyl rings (C1—C6) is 79.09 (5)°. The bond lengths (Allen et al.,1987) and angles are within normal ranges and comparable to those in closely related crystal structures (Shahani et al., 2009, 2010a,b).

In the crystal packing (Fig. 2), pairs of intermolecular O3—H1O3···N1, N2—H1N2···O2 hydrogen bonds form dimers between neighbouring molecules, generating R²₂(8) ring motifs (Bernstein et al., 1995). These dimers are linked into two-dimensional arrays parallel to the ac plane by intermolecular O3—H1O3···N1 and N2—H1N2···O2 hydrogen bonds (Table 1). The crystal structure is also stabilized by C12—H12A···Cg1 interactions (Table 1) involving the C7–C9/N1/N2 pyrazole ring.

Experimental

The compound 5-pentyl-4-(phenylsulfonyl)-1H-pyrazol-3-ol was synthesized according to the procedure available in the literature (Ragavan et al., 2009, 2010), which in turn was dissolved using a THF/water (1:1) mixture. Oxone (4 mmol) was then added and the solution was stirred at room temperature for 3 h. The reaction mixture was diluted with water (20 ml), and then was extracted with ethyl acetate (2 x 50 ml). The combined extract was washed with water (20 ml) and brine solution (10 ml). Crystallization was carried out using absolute ethanol.