1-[3-(2,4-Dichloro-5-fluoro­phen­yl)-5-(3-methyl-2-thien­yl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone

N Anuradha; A Thiruvalluvar; M Mahalinga; R J Butcher

doi:10.1107/S1600536808033837

. 2008 Oct 22;64(Pt 11):o2160. doi: 10.1107/S1600536808033837

1-[3-(2,4-Dichloro-5-fluorophenyl)-5-(3-methyl-2-thienyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone

N Anuradha ^a, A Thiruvalluvar ^a,^*, M Mahalinga ^b, R J Butcher ^c

PMCID: PMC2959565 PMID: 21581020

Abstract

In the title molecule, C₁₆H₁₃Cl₂FN₂OS, the dihedral angle between the thiophene and benzene rings is 80.34 (12)°. The pyrazoline ring is in an envelope conformation, and the plane through the four coplanar atoms makes dihedral angles of 85.13 (9) and 6.89 (10)° with the thiophene and benzene rings, respectively. The C and O atoms of the acetyl group are nearly coplanar with the attached pyrazoline ring. In the crystal structure, inversion dimers arise from pairs of intermolecular C—H⋯O hydrogen bonds. A short intermolecular Cl⋯S contact of 3.4250 (13) Å is also found.

Related literature

For a related crystal structure, see: Thiruvalluvar et al. (2007 ▶).

Experimental

Crystal data

C₁₆H₁₃Cl₂FN₂OS
M _r = 371.25
Triclinic,
a = 7.2240 (5) Å
b = 8.8642 (4) Å
c = 14.0518 (9) Å
α = 100.794 (5)°
β = 103.307 (6)°
γ = 101.003 (5)°
V = 833.99 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.53 mm⁻¹
T = 295 (2) K
0.52 × 0.43 × 0.35 mm

Data collection

Oxford Diffraction R Gemini diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▶) T _min = 0.786, T _max = 1.000 (expected range = 0.654–0.831)
12358 measured reflections
5445 independent reflections
3028 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.179
S = 1.12
5445 reflections
210 parameters
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033837/wn2286sup1.cif

e-64-o2160-sup1.cif^{(22KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808033837/wn2286Isup2.hkl

e-64-o2160-Isup2.hkl^{(261.2KB, 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
C2—H2A⋯O1ⁱ	0.96	2.58	3.533 (4)	171

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Symmetry code: (i) Inline graphic .

Acknowledgments

AT thanks the UGC, India, for the award of a Minor Research Project [file No. MRP-2355/06(UGC-SERO), Link No. 2355, 10/01/2007]. RJB acknowledges the NSF-MRI program for funding to purchase the X-ray CCD diffractometer.

supplementary crystallographic information

Comment

A great deal of attention has been paid to the synthesis and structural aspects of pyrazolines, as witnessed by continued activity in this area (Thiruvalluvar et al., 2007).

In the title molecule, C₁₆H₁₃Cl₂FN₂OS, Fig.1., the dihedral angle between the thiophene and benzene rings is 80.34 (12)°. The pyrazoline ring is in an envelope conformation and the plane through the four coplanar atoms makes dihedral angles of 85.13 (9)° and 6.89 (10)° with the thiophene and benzene rings, respectively. The acetyl group, except for the hydrogen atoms, is nearly coplanar with the attached pyrazoline ring. An intermolecular C2—H2A···O1(-1 - x, 1 - y, -z) hydrogen bond is found in the crystal structure (Table 1). Further, a short intermolecular Cl4···S21(1-x,1-y,1-z) contact of 3.4250 (13) Å is also found in the crystal structure.

Experimental

A mixture of 1-(2,4-dichloro-5-fluorophenyl)-3-(3-methylthien-2-yl) prop-2-en-1-one (5 g, 0.016 mol) and a molar equivalent of hydrazine hydrate (80%) in glacial acetic acid (25 ml) was heated on a water bath at 363–365 K for 5–6 h. The reaction mass was then poured into ice-cold water. The solid obtained was filtered, washed with water, dried and crystallized from methanol to yield the title compound. Yield 5.5 g (93.5%).