4-{[5-(4-Chloro­phen­yl)-1-(4-fluoro­phen­yl)-1H-pyrazol-3-yl]carbon­yl}-N-ethyl­piperazine-1-carboxamide

Tara Shahani; Hoong-Kun Fun; V Vijayakumar; R Venkat Ragavan; S Sarveswari

doi:10.1107/S1600536811023178

. 2011 Jun 18;67(Pt 7):o1747–o1748. doi: 10.1107/S1600536811023178

4-{[5-(4-Chlorophenyl)-1-(4-fluorophenyl)-1H-pyrazol-3-yl]carbonyl}-N-ethylpiperazine-1-carboxamide

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

PMCID: PMC3151813 PMID: 21837133

Abstract

The asymmetric unit of the title compound, C₂₃H₂₃ClFN₅O₂, contains two crystallographically independent molecules. In one molecule, the pyrazole ring makes dihedral angles of 43.93 (7) and 35.82 (7)°, respectively, with the fluoro- and chloro-substituted benzene rings, while the corresponding angles in the other molecule are 52.26 (8) and 36.85 (7)°. The piperazine rings adopt chair conformations. In the crystal, adjacent molecules are connected via intermolecular N—H⋯O, C—H⋯F, C—H⋯N and C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane. The crystal structure is further stabilized by a weak π–π interaction with a centroid–centroid distance of 3.6610 (8) Å and by C—H⋯π interactions.

Related literature

For our ongoing research on the synthesis of pyrazole derivatives with antimicrobial activity, see: Ragavan et al. (2009 ▶, 2010 ▶); Ragavan & Vijayakumar (2011 ▶). For related structures, see: Shahani et al. (2009 ▶, 2010a ▶,b ▶,c ▶). For bond-length data, see: Allen et al. (1987 ▶). For ring conformations, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₃H₂₃ClFN₅O₂
M _r = 455.91
Monoclinic,
a = 25.8566 (6) Å
b = 10.0475 (2) Å
c = 16.8822 (4) Å
β = 92.525 (1)°
V = 4381.64 (17) Å³
Z = 8
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 296 K
0.59 × 0.21 × 0.10 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.884, T _max = 0.978
59628 measured reflections
15831 independent reflections
10263 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.051
wR(F ²) = 0.136
S = 1.08
15831 reflections
587 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.48 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/S1600536811023178/is2729sup1.cif

e-67-o1747-sup1.cif^{(37.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811023178/is2729Isup2.hkl

e-67-o1747-Isup2.hkl^{(773.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811023178/is2729Isup3.cml

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

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

Cg1 and Cg4 are the centroids of the N4A/N5A/C9A–C11A and C18A–C23A rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1B—H1NB⋯O1Aⁱ	0.876 (18)	2.060 (19)	2.9284 (16)	171.1 (16)
N1A—H1NA⋯O1Bⁱⁱ	0.905 (18)	2.096 (18)	2.9667 (16)	161.1 (15)
C4A—H4AA⋯O1Bⁱⁱⁱ	0.97	2.55	3.4393 (19)	152
C4A—H4AB⋯O1Bⁱⁱ	0.97	2.49	3.4466 (17)	168
C6A—H6AA⋯N4A	0.97	2.18	2.9468 (17)	135
C13A—H13A⋯F1A^iv	0.93	2.52	3.4330 (16)	166
C4B—H4BA⋯O1Aⁱ	0.97	2.31	3.2757 (17)	175
C22A—H22A⋯O2A^v	0.93	2.41	3.3167 (18)	164
C22B—H22B⋯O2B^iv	0.93	2.38	3.1927 (18)	146
C23A—H23A⋯O2Bⁱⁱⁱ	0.93	2.47	3.2482 (18)	141
C6B—H6BB⋯N5B	0.97	2.18	2.9505 (17)	136
C7B—H7BA⋯Cg1^vi	0.97	2.59	3.5216 (16)	162
C2A—H2AB⋯Cg4^vii	0.97	2.95	3.5831 (15)	124

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

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.

supplementary crystallographic information

Comment

As part of our ongoing research aiming on the synthesis of novel pyrazole derivatives as new antimicrobial compounds, herein we report the synthesis of title compound (Ragavan et al., 2009, 2010; Ragavan & Vijayakumar, 2011)

The asymmetric unit of title compound (Fig. 1), contains two crystallographically independent molecules (A & B) in which the pyrazole units are essentially planar, with maximum deviations of 0.008 (1) Å for atom C8A (molecule A) and 0.002 (1) Å for atom C9B (molecule B). The dihedral angle between the pyrazole (N4A/N5A/C9A–C11A)/(N5B/N6B/C9B–C11B) and piperazine rings (N2A/N3A/C4A–C7A)/(N2B/N3B/C4B–C7B) is 1.72 (8) (molecule A) and 22.74 (7)° (molecule B) and that between the fluoro (C18A–C23A)/(C18B–C23B) and chloro-substituted (C12A–C17A)/(C12B–C17B) phenyl rings is 53.97 (7) for molecule A and 55.06 (7)° for molecule B. In each molecule, the piperazine (N2A/N3A/C4A–C7A)/(N2B/N3B/C4B–C7B) ring adopts a chair conformation with puckering parameters (Cremer & Pople, 1975) Θ = 0.5441 (15) Å, θ = 177.80 (16)° and φ = 120 (4)° (molecule A) and Θ = 0.5536 (15) Å, θ = 2.47 (14)° and φ = 329 (4)° (molecule B). The bond lengths (Allen et al., 1987) and angles are within normal ranges and comparable to those closely related structures (Shahani et al., 2009, 2010a,b).

In the crystal structure (Fig. 2), the adjacent molecules are connected via intermolecular N1B—H1NB···O1A, N1A—H1NA···O1B, C4A—H4AA···O1B, C4A—H4AB···O1B, C6A—H6AA···N4A, C13A—H13A···F1A, C4B—H4BA···O1A, C22A—H22A···O2A, C22B—H22B···O2B,C23A—H23A···O2B and C6B—H6BB···N5B hydrogen bonds (Table 1), forming a two-dimensional network parallel to the bc-plane. Furthermore, the crystal structure is stabilized by weak π–π interactions between pyrazole (N4A/N5A/C9A–C11A)/(N5B/C6B/C9B–C11B) rings [centroid–centroid distance = 3.6610 (8) Å; 1 - x, 1/2 + y, 1/2 - z] and C—H···π interactions, involving Cg1 (N4A/N5A/C9A–C11A) and Cg4 (C18A–C23A) rings.

Experimental

The compound has been synthesized using the method available in the literature (Ragavan et al., 2010) and recrystallized with chloroform-methanol 1:1 mixture yielding colourless crystals. M.p.: 225.4–226.1 °C