5-Ethyl-2-(4-fluoro­phen­yl)-4-phen­oxy-1H-pyrazol-3(2H)-one

Tara Shahani; Hoong-Kun Fun; R Venkat Ragavan; V Vijayakumar; M Venkatesh

doi:10.1107/S1600536811000754

. 2011 Jan 22;67(Pt 2):o475. doi: 10.1107/S1600536811000754

5-Ethyl-2-(4-fluorophenyl)-4-phenoxy-1H-pyrazol-3(2H)-one

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

PMCID: PMC3051690 PMID: 21523133

Abstract

In the title compound, C₁₇H₁₅FN₂O₂, the essentially planar pyrazole ring [maximum deviation = 0.026 (1) Å] makes dihedral angles of 72.06 (7) and 33.05 (7)°, with the phenyl and fluorobenzene rings, respectively. The dihedral angle between the two six-membered rings is 87.88 (7)°. In the crystal, intermolecular N—H⋯O and C—H⋯F hydrogen bonds link the molecules into layers lying parallel to the bc plane.

Related literature

For pyrazole derivatives and their microbial activity, see: Ragavan et al. (2009 ▶, 2010 ▶). For the synthesis, see: Ragavan et al. (2009 ▶). For related structures, see: Shahani et al. (2009 ▶, 2010a ▶,b ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For bond-length data, see: Allen et al. (1987 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₇H₁₅FN₂O₂
M _r = 298.31
Monoclinic,
a = 15.332 (2) Å
b = 8.6833 (14) Å
c = 11.6066 (19) Å
β = 109.916 (3)°
V = 1452.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.55 × 0.14 × 0.08 mm

Data collection

Bruker APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.947, T _max = 0.992
12927 measured reflections
4247 independent reflections
3207 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.119
S = 1.05
4247 reflections
204 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.24 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/S1600536811000754/hb5788sup1.cif

e-67-0o475-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811000754/hb5788Isup2.hkl

e-67-0o475-Isup2.hkl^{(208.1KB, 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
N2—H1N2⋯O2ⁱ	0.899 (18)	1.803 (18)	2.6865 (14)	167.1 (16)
C11—H11A⋯F1ⁱⁱ	0.93	2.52	3.3441 (16)	147

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

Acknowledgments

HKF and TSH thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSH also thanks USM for the award of a research fellowship. VV is grateful to the DST–India for funding through the Young Scientist Scheme (Fast Track Proposal).

supplementary crystallographic information

Comment

Antibacterial and antifungal activities of the azoles are most widely studied and some of them are in clinical practice as anti-microbial agents. However, the azole-resistant strain had led to the development of new antimicrobial compounds. In particular pyrazole derivatives are extensively studied and used as antimicrobial agents. Pyrazole is an important class of heterocyclic compounds and many pyrazole derivatives are reported to have the broad spectrum of biological properties, such as anti-inflammatory, antifungal, herbicidal,anti-tumour, cytotoxic, molecular modelling, and antiviral activities. Pyrazole derivatives also act as antiangiogenic agents, A3 adenosine receptor antagonists, neuropeptide YY5 receptor antagonists, kinase inhibitor for treatment of type 2 diabetes, hyperlipidemia, obesity, and thrombopiotinmimetics. Recently urea derivatives of pyrazoles have been reported as potent inhibitors of p38 kinase. Since the high electronegativity of halogens (particularly chlorine and fluorine) in the aromatic part of the drug molecules play an important role in enhancing their biological activity, we are interested to have 4-fluoro or 4-chloro substitution in the aryls of 1,5-diaryl pyrazoles. As part of our on-going research aiming the synthesis of new antimicrobial compounds, we have reported the synthesis of novel pyrazole derivatives and their microbial activities (Ragavan et al., 2009; 2010). The structure of the title compound, (I), is presented here.

In the title compound (Fig. 1), the molecule consists of two phenyl (C10—C15 and C1—C6) and one pyrazole (N1/N2/C7—C9) rings, all rings are essentially planar. The pyrazole ring (maximum deviation of 0.026 (1) Å at atom N1) makes dihedral angles of 72.06 (7) and 33.05 (7)°, with phenyl (C10—C15) and fluoro substituted phenyl (C1—C6) rings, respectively. The dihedral angle between the two six-membered rings,(C1—C6) and (C10—C15), is 87.88 (7)°. The bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to the closely related structures (Shahani et al.,2009; 2010a,b).

In the crystal (Fig. 2), intermolecular N2–H1N2···O2 and C11–H11A···F1 (Table 1) hydrogen bonds link the molecules into two-dimensional arrays parallel to the bc plane.

Experimental

The compound was synthesized using the literature method (Ragavan et al.,2009) and recrystallized using an ethanol-chloroform 1:1 mixture to yield colourless needles of (I). Yield: 61%. M.p.: 441 K.