1,1′-Bis(4-fluoro­phen­yl)-3,3′-diisobutyl-4,4′-diphen­oxy-1H,1′H-4,4′-bipyrazole-5,5′(4H,4′H)-dione

Hoong-Kun Fun; Madhukar Hemamalini; R Venkat Ragavan; V Vijayakumar; M Venkatesh

doi:10.1107/S1600536811011664

. 2011 Apr 7;67(Pt 5):o1036. doi: 10.1107/S1600536811011664

1,1′-Bis(4-fluorophenyl)-3,3′-diisobutyl-4,4′-diphenoxy-1H,1′H-4,4′-bipyrazole-5,5′(4H,4′H)-dione

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

PMCID: PMC3089260 PMID: 21754364

Abstract

In the title compound, C₃₈H₃₆F₂N₄O₄, the pyrazole rings form dihedral angles of 50.02 (4) and 18.05 (4)° with their attached fluorobenzene rings, and make dihedral angles of 76.08 (4) and 73.54 (5)° with the aromatic ring of the attached phenoxy group. In the crystal, the molecules are connected by weak C—H⋯π interactions.

Related literature

For the synthesis and applications of pyrazole derivatives, see: Venkat Ragavan et al. (2009 ▶, 2010 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₃₈H₃₆F₂N₄O₄
M _r = 650.71
Monoclinic,
a = 11.3875 (5) Å
b = 11.4582 (5) Å
c = 13.4885 (6) Å
β = 109.752 (1)°
V = 1656.43 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100 K
0.53 × 0.21 × 0.14 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.953, T _max = 0.987
26247 measured reflections
6956 independent reflections
6490 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.097
S = 1.03
6956 reflections
437 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.19 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/S1600536811011664/rz2574sup1.cif

e-67-o1036-sup1.cif^{(30.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811011664/rz2574Isup2.hkl

e-67-o1036-Isup2.hkl^{(333.5KB, hkl)}

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

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

Cg1 is the centroid of the N2=C8 double bond. Cg3 and Cg5 are the centroids of the C1–C6 and C19–C24 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15A⋯Cg5ⁱ	0.93	2.82	3.6941 (14)	157
C20—H20A⋯Cg1	0.93	2.54	2.9632 (12)	135
C29—H29A⋯Cg3ⁱⁱ	0.93	2.82	3.4701 (15)	128
C36—H36A⋯Cg3ⁱ	0.98	2.91	3.7529 (15)	145

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

Acknowledgments

HKF and MH thank the Malaysian Government and Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160. MH also thanks Universiti Sains Malaysia for a post-doctoral 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 strains has 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 compound and many pyrazole derivatives are reported to have the broad spectrum of biological activities, 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 (Venkat Ragavan et al., 2009, 2010).

In the molecule of the title compound (Fig. 1), the pyrazole rings (N1–N2/C7–C9; N3–N4/C10–C12) form dihedral angles of 50.02 (4) and 18.05 (4)° with the attached benzene rings (C1–C6; C13–C18), and of 76.08 (4) and 73.54 (5)° with the aromatic ring of the attached phenoxy group (C19–C24; C25–C30). In the crystal structure (Fig. 2), there is no classical hydrogen bond and stabilization is provided by weak C—H···π interactions (Table 1), involving the centroids of the N2═C8 double bond (centroid Cg1), C1–C6 ring (centroid Cg3) and C19–C24 ring (centroid Cg5).

Experimental

1-(4-Fluorophenyl)-3-isobutyl-4-phenoxy-1H-pyrazole- 5(4H)-one was synthesized using the method reported in the literature (Venkat Ragavan et al., 2010) and was converted into the title compound under the experimental condition. Single crystals of the title compound were obtained byu slow evaporation of an ethanol / chloroform (1:1 v/v) solution. Yield: 52%. M. p. 198 °C.