5-(4-Fluoro­phen­yl)-3-(4-methyl­phen­yl)-4,5-dihydro-1H-pyrazole-1-carbothio­amide

Bakr F Abdel-Wahab; Hanan A Mohamed; Rizk E Khidre; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536813004194

. 2013 Feb 16;69(Pt 3):o385–o386. doi: 10.1107/S1600536813004194

5-(4-Fluorophenyl)-3-(4-methylphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamide

Bakr F Abdel-Wahab ^a,^‡, Hanan A Mohamed ^a, Rizk E Khidre ^b, Seik Weng Ng ^c,^d, Edward R T Tiekink ^c,^*

PMCID: PMC3588501 PMID: 23476571

Abstract

The central pyrazole ring in the title compound, C₁₇H₁₆FN₃S, adopts an envelope conformation with the methine C atom bearing the 4-fluorophenyl substituent as the flap atom. Whereas the tolyl ring is slightly twisted out of the least-squares plane through the pyrazole ring [dihedral angle = 13.51 (11)°], the fluorobenzene ring is almost perpendicular [dihedral angle = 80.21 (11)°]. The thioamide group is almost coplanar with the N—N bond of the ring [N—N—C—N torsion angle = 1.2 (3)°] and the amine group forms an intramolecular hydrogen bond with a ring N atom. In the crystal, supramolecular double layers in the bc plane are formed via N—H⋯S, N—H⋯F and C—H⋯F interactions.

Related literature

For the biological activity of pyrazolin-1-ylthiazoles, see: Abdel-Wahab et al. (2009 ▶, 2012 ▶); Chimenti et al. (2010 ▶). For related structures, see: Nonthason et al. (2011 ▶); Chantrapromma et al. (2012 ▶).

Experimental

Crystal data

C₁₇H₁₆FN₃S
M _r = 313.39
Monoclinic,
a = 14.4154 (10) Å
b = 11.3197 (9) Å
c = 9.5575 (8) Å
β = 103.991 (8)°
V = 1513.3 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 295 K
0.30 × 0.20 × 0.10 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.772, T _max = 1.000
9303 measured reflections
3500 independent reflections
2370 reflections with I > 2σ(I)
R _int = 0.038

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.122
S = 1.04
3500 reflections
200 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Click here for additional data file.^{(19.3KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813004194/hg5291sup1.cif

e-69-0o385-sup1.cif^{(19.3KB, cif)}

Click here for additional data file.^{(171.6KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813004194/hg5291Isup2.hkl

e-69-0o385-Isup2.hkl^{(171.6KB, hkl)}

Click here for additional data file.^{(5.8KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813004194/hg5291Isup3.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
N3—H31⋯N2	0.88	2.23	2.611 (3)	106
N3—H31⋯F1ⁱ	0.88	2.41	3.255 (2)	162
N3—H32⋯S1ⁱⁱ	0.88	2.83	3.538 (2)	138
C16—H16B⋯F1ⁱⁱⁱ	0.96	2.55	3.478 (3)	163

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

Acknowledgments

We thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR-MOHE/SC/12).

supplementary crystallographic information

Comment

The title compound (I) was investigated crystallographically in connection with the established biological activities exhibited by pyrazolin-1-ylthiazoles (Abdel-Wahab et al., 2012; Abdel-Wahab et al., 2009; Chimenti et al., 2010).

The central pyrazolyl ring in (I), Fig. 1, adopts an envelope conformation with the methine-C7 atom being the flap atom. The tolyl ring is slightly twisted out of the least-squares plane through the pyrazolyl ring, forming a dihedral angle of 13.51 (11)°. By contrast, the fluorobenzene ring is almost perpendicular to the five-membered ring [dihedral angle = 80.21 (11)°]. Finally, the thioamide residue is co-planar with the N2—N1—C17—N3 torsion angle being 1.2 (3)°; the amine group is orientated towards the ring-N2 atom, forming a hydrogen bond, Table 1. Similar conformations have been observed in related structures bearing two six-membered rings (Nonthason et al., 2011; Chantrapromma et al., 2012).

The F atom proves to be pivotal in providing stability to the crystal structure of (I). Thus, in addition to forming an intramolecular N—H···N2 hydrogen bond, the amine-H31 atom forms a hydrogen bond to the F1 atom, Table 1. The second amine-H32 atom hydrogen bonds to a thione so that a supramolecular chain along the c axis ensues, Fig. 2. Chains stack along the b axis to form a row and centrosymmetrically related rows inter-digitate along the a axis allowing for the formation methylene-C16—H···F1 interactions and, therefore, double layers, Fig. 2.

Experimental

A mixture of 5-(4-fluorophenyl)-3-p-tolyl-4,5-dihydro-1H-pyrazole-1-carbothioamide (0.31 g, 0.001 M) and 2-bromo-1-(4-chlorophenyl)ethanone (0.23 g, 0.001 M) in anhydrous ethanol (30 ml) was heated under reflux for about 4 h. The resultant solid was filtered and dried. Re-crystallization was by slow evaporation of DMF solution of (I) which yielded colourless crystals in 61% yield. M.pt: 513–514 K.