1-[5-(4-Bromo­phen­yl)-3-(4-fluoro­phen­yl)-4,5-dihydro-1H-pyrazol-1-yl]butan-1-one

Hoong-Kun Fun; Wan-Sin Loh; M Sapnakumari; B Narayana; B K Sarojini

doi:10.1107/S1600536812034368

. 2012 Aug 8;68(Pt 9):o2655–o2656. doi: 10.1107/S1600536812034368

1-[5-(4-Bromophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]butan-1-one

Hoong-Kun Fun ^a,^*,^‡, Wan-Sin Loh ^a,^§, M Sapnakumari ^b, B Narayana ^b, B K Sarojini ^c

PMCID: PMC3435682 PMID: 22969553

Abstract

In the title compound, C₁₉H₁₈BrFN₂O, the benzene rings form dihedral angles of 5.38 (7) and 85.48 (7)° with the mean plane of the 4,5-dihydro-1H-pyrazole ring (r.m.s. deviation = 0.0849 Å), which approximates to an envelope conformation with the –CH₂– group as the flap. The dihedral angle between the benzene rings is 82.86 (7)°. In the crystal, C—H⋯F and C—H⋯O hydrogen bonds link the molecules to form inversion dimers and together these generate chains along [011]. The crystal packing also features C—H⋯π interactions.

Related literature

For background to pyrazoline derivatives, see: Fun et al. (2010 ▶); Samshuddin et al. (2011 ▶). For related structures, see: Fun, Quah et al. (2012 ▶); Fun, Loh et al. (2012 ▶). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₁₉H₁₈BrFN₂O
M _r = 389.26
Triclinic,
a = 6.7502 (3) Å
b = 10.1253 (5) Å
c = 13.7792 (8) Å
α = 105.354 (1)°
β = 98.976 (1)°
γ = 107.369 (1)°
V = 838.01 (7) Å³
Z = 2
Mo Kα radiation
μ = 2.47 mm⁻¹
T = 100 K
0.28 × 0.23 × 0.08 mm

Data collection

Bruker SMART APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.546, T _max = 0.823
17838 measured reflections
4816 independent reflections
4458 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.066
S = 1.06
4816 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 0.49 e Å⁻³
Δρ_min = −0.63 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 datablock(s) global, I. DOI: 10.1107/S1600536812034368/hb6918sup1.cif

e-68-o2655-sup1.cif^{(27.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812034368/hb6918Isup2.hkl

e-68-o2655-Isup2.hkl^{(235.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812034368/hb6918Isup3.cml

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

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

Cg1 and Cg2 are the centroids of the C1–C5 and C10–C15 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11A⋯F1ⁱ	0.95	2.37	3.1873 (17)	144
C14—H14A⋯O1ⁱⁱ	0.95	2.57	3.1832 (16)	122
C5—H5A⋯Cg2ⁱⁱⁱ	0.95	2.68	3.5453 (15)	152
C17—H17B⋯Cg1^iv	0.99	2.70	3.5488 (14)	144

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

Acknowledgments

HKF and WSL thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160). WSL also thanks the Malaysian government and USM for the post of Research Officer under the Research University Grant (No. 1001/PFIZIK/811160). BN thanks the UGC for financial assistance through SAP and BSR one time grant for the purchase of chemicals.

supplementary crystallographic information

Comment

In continuation of our work on synthesis of pyrazoline derivatives (Fun et al., 2010; Samshuddin et al., 2011), the title compound is prepared and its crystal structure is reported.

In the title compound, Fig. 1, the benzene rings (C1–C6 & C10–C15) form dihedral angles of 5.38 (7) and 85.48 (7)°, respectively, with the mean plane of 4,5-dihydro-1H-pyrazole ring (N1/N2/C7–C9, r.m.s. deviation = 0.0849 Å). The dihedral angle between the two benzene rings is 82.86 (7) °. Bond lengths and angles are comparable with those in related structures (Fun, Quah et al., 2012; Fun, Loh et al., 2012).

In the crystal packing as shown in Fig. 2, C11—H11A···F1 and C14—H14A···O1 hydrogen bonds (Table 1) link the molecules to form dimers, generating chains along the [011]. The crystal packing is further consolidated by C17—H17B···Cg1 and C5—H5A···Cg2 (Table 1) interactions, where Cg1 and Cg2 are the centroids of C1–C5 and C10–C15 benzene rings, respectively.

Experimental

A mixture of (2E)-3-(4-bromophenyl)-1-(4-fluorophenyl)prop-2-en-1-one (3.05 g, 0.01 mol) and hydrazine hydrate (0.48 ml, 0.01 mol) in 30 ml butyric acid was refluxed for 6 h. The reaction mixture was cooled and poured into 50 ml ice-cold water. The precipitate was collected by filtration and purified by recrystallization from ethanol. Colourless plates were grown from acetone solution by slow evaporation method. M. p.: 383–385 K.