(2,3-Difluoro­phen­yl)(4-tosyl­piperazin-1-yl)methanone

S Sreenivasa; K E ManojKumar; P A Suchetan; J Tonannavar; Yashshwita Chavan; B S Palakshamurthy

doi:10.1107/S1600536812051690

. 2013 Jan 4;69(Pt 2):o185. doi: 10.1107/S1600536812051690

(2,3-Difluorophenyl)(4-tosylpiperazin-1-yl)methanone

S Sreenivasa ^a,^*, K E ManojKumar ^a, P A Suchetan ^b, J Tonannavar ^c, Yashshwita Chavan ^c, B S Palakshamurthy ^d

PMCID: PMC3569247 PMID: 23424470

Abstract

In the title compound, C₁₈H₁₈F₂N₂O₃S, the piperazine ring adopts a chair conformation. The dihedral angle between the sulfonyl-bound benzene ring and the best fit plane throught the six non-H atoms of the piperazine ring is 69.4 (2)°, while those between the fluorobenzene and sulfonyl rings and the fluorobenzene and piperazine rings are 30.97 (2) and 75.98 (2)°, respectively. In the crystal, molecules are connected to form a tetrameric unit through C—H⋯O hydrogen bonds. The structure is further stabilized by weak intermolecular C—H⋯F interactions, generating C(8) and C(7) chains running along [100].

Related literature

For the synthesis, characterization and biological activity of piperazine and its derivatives, see: Gan et al. (2009a ▶,b ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₈H₁₈F₂N₂O₃S
M _r = 380.40
Monoclinic,
a = 17.0456 (4) Å
b = 7.6026 (1) Å
c = 15.5113 (3) Å
β = 113.513 (1)°
V = 1843.22 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 298 K
0.28 × 0.26 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.942, T _max = 0.958
11988 measured reflections
2359 independent reflections
1930 reflections with I > 2σ(I)
R _int = 0.023
θ_max = 22.4°

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.092
S = 1.06
2359 reflections
236 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: APEX2 and SAINT-Plus (Bruker, 2009 ▶); data reduction: SAINT-Plus and XPREP (Bruker,2009 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(26.5KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812051690/sj5290sup1.cif

e-69-0o185-sup1.cif^{(26.5KB, cif)}

Click here for additional data file.^{(115.9KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812051690/sj5290Isup2.hkl

e-69-0o185-Isup2.hkl^{(115.9KB, hkl)}

Click here for additional data file.^{(6.7KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812051690/sj5290Isup3.cml

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
C4—H4⋯O3ⁱ	0.93	2.58	3.495 (3)	169
C8—H8A⋯O3ⁱⁱ	0.97	2.34	3.255 (3)	157
C10—H10B⋯O1ⁱⁱⁱ	0.97	2.48	3.402 (3)	159
C8—H8B⋯F1^iv	0.97	2.57	3.518 (3)	165
C11—H11A⋯F2^iv	0.97	2.56	3.296 (3)	133

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

Acknowledgments

The authors thank Dr S. C. Sharma, Vice Chancellor, Tumkur University, for his constant encouragement. JT also thanks the DST, New Delhi, for the SCXRD facility under the PURSE Grant (SR/S9/Z-23/2008/11, 2009) at USIC, Karnatak University.

supplementary crystallographic information

Comment

Numerous piperazine derivatives such as aryl amides, sulphonamides, Mannich bases, Schiff's bases, thiazolidinones, azetidinones, imidazolinones have shown a wide spectrum of biological activities viz. anti-inflammatory, antibacterial, antimalarial, anticonvulsant, antipyretic, antitumor, anthelmintics, analgesic, antidepressant, antifungal, antitubercular, anticancer, antidiabetic effects (Gan et al., 2009a, 2009b). Keeping this in mind, we synthesized the title compound to study its crystal structure.

The compound crystallizes in monoclinic crystal system and the space group P2₁/c. In the crystal structure, the piperazine ring adopts chair conformation. The dihedral angle between the sulfonyl bound benzene ring and the best fit plane through all six atoms of the piperazine ring is 69.4 (2)°, while those between the fluorobenzene and the sulfonyl rings and the fluorobenzene and the piperazine rings are 30.97 (2)° and 75.98 (2)° respectively. In the crystal structure molecules form a tetrameric unit generating alternate R₂²(22), (C8—H8A···O3, C10—H10B···O1) and inversion related C4—H4···O3 R₂²(10) rings (Bernstein et al.1995). The structure is further stabilized by weak intermolecular C11—H11A···F2 and C8—H8B···F1 interactions.

Experimental

1-Tosylpiperazine (0.01 mmol) and triethylamine (0.02 mmol) were dissolved in 10 ml of dichloromethane (CH₂Cl₂). The mixture was cooled to 0°C and 1-propanephosphonic acid anhydride (0.02 mmol) and 2,4-diflurobenzoic acid (0.01 mmol) added. The reaction mixture was stirred at 80°C for 14 h. The reaction was monitored by TLC and the solvent removed yielding the crude product. The crude mass was purified by chromatography on 230–400 silica gel with petroleum ether and ethyl acetate as eluents. Single crystals of the title compound were obtained from slow evaporation of a solution of the compound in petroleum ether and ethyl acetate (1:4).