2,2′-(1-Phenyl-1H-pyrazole-3,5-di­yl)diphenol

Sumeera Ikram; Muhammad Zia ul Haq; Amir Badshah; Aurangzeb Hasan; Michael Bolte

doi:10.1107/S1600536809001226

. 2009 Jan 23;65(Pt 2):o364. doi: 10.1107/S1600536809001226

2,2′-(1-Phenyl-1H-pyrazole-3,5-diyl)diphenol

Sumeera Ikram ^a, Muhammad Zia ul Haq ^a, Amir Badshah ^a, Aurangzeb Hasan ^a,^*, Michael Bolte ^b

PMCID: PMC2968261 PMID: 21581962

Abstract

The title compound, C₂₁H₁₆N₂O₂, was derived from 1-(2-hydroxyphenyl)-3-(-methoxyphenyl)propane-1,3-dione. The molecular structure of the title compound is stabilized by an intramolecular O—H⋯N hydrogen bond. The dihedral angle between the hydroxyphenyl ring involved in this intramolecular hydrogen bond and the pyrazole ring is significantly smaller [10.07 (6)°] than the dihedral angle between the pyrazole and the other hydroxyphenyl ring [36.64 (5)°]. The benzene ring makes a dihedral angle of 54.95 (3)° with the pyrazole ring. The crystal packing is stabilized by O—H⋯O and O—H⋯N hydrogen bonds.

Related literature

For the biological activity of pyrazoles, see: Beeam et al. (1984 ▶). For the preparation of new materials for medicine, see: Elguero (1983 ▶). For the coordination chemistry of pyrazoles, see: Bonati (1980 ▶). For their use as analytical reagents, see: Freyer & Radeglia (1981 ▶). For the synthesis of 1-(2′-hydroxyphenyl)-3-(2′′-methoxyphenyl)propane-1,3-dione, see: Ahmad et al. (1997 ▶).

Experimental

Crystal data

C₂₁H₁₆N₂O₂
M _r = 328.36
Monoclinic,
a = 9.7034 (8) Å
b = 11.7407 (9) Å
c = 14.9486 (14) Å
β = 104.294 (7)°
V = 1650.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 173 (2) K
0.48 × 0.46 × 0.46 mm

Data collection

Stoe IPDSII two-circle diffractometer
Absorption correction: none
12165 measured reflections
3799 independent reflections
3235 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.101
S = 1.03
3799 reflections
235 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2001 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶) and XP in SHELXTL-Plus (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809001226/bx2193sup1.cif

e-65-0o364-sup1.cif^{(20.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809001226/bx2193Isup2.hkl

e-65-0o364-Isup2.hkl^{(186.3KB, 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
O2—H2⋯O1ⁱ	0.94 (2)	1.81 (2)	2.7524 (12)	176.6 (19)
O1—H1⋯N2	0.947 (19)	1.718 (19)	2.5863 (12)	150.9 (17)

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Symmetry code: (i) Inline graphic .

Acknowledgments

AB is grateful to the Higher Education Commission of Pakistan for a grant.

supplementary crystallographic information

Comment

Pyrazoles are important because of their potential for biological activity. They have antipuretic, anti-inflammatory and antirheumatic effects (Beeam et al., 1984). Both traditional and new scientific methods have been used to prepare new materials for medicine (Elguero et al., 1983) and agriculture (Trofimenko, 1972). Neutral and anionic pyrazoles are excellent ligands and their co-ordination chemistry has been extensively studied (Bonati, 1980). Pyrazoles are also used as analytical reagents (Freyer et al., 1981) The molecular structure of the title compound is stabilized by an intramolecular O-H···N hydrogen bond. The dihedral angle between the hydroxyphenyl ring involved in this intramolecular hydrogen bond is significantly smaller [10.07 (6)°] than the dihedral angle between the pyrazole and the other hydroxyphenyl ring [36.64 (5)°]. The phenyl ring makes a makes dihedral angle of 54.95 (3)° with the pyrazol ring. The crystal packing is stabilized by O-H···O hydrogen bonds.

Experimental

1-(2'-hydroxyphenyl)-3-(2"-methoxyphenyl) propane-1,3-dione (I) was prepared by a modified Baker Venkataram rearrangement as reported earlier (Ahmad et al. 1997). 1-Phenyl-3,5-bis(2'-hydroxy phenyl)phyrazole(III) was synthesized by demethylation of 2-(5-(2-methoxyphenyl)-1-phenyl-1H-pyrazol-3-yl)phenol(II), which was prepared by refluxing 1-(2'-hydroxyphenyl)-3-(2"-methoxyphenyl) propane-1,3-dione (2.7 g, 10 mmol) with phenyl hydrazine (1.08 g,0.99 ml, 10 mmol) in 100 ml absolute ethanol for seven hours as shown in Fig. 3. The product was recrystallized using absolute ethanol. (yield: 90%, m.p: 473k)