3-(4-Bromo­phen­yl)-5-[4-(dimethyl­amino)­phen­yl]-4,5-dihydro-1H-pyrazole-1-carbothio­amide

Hoong-Kun Fun; Thitipone Suwunwong; Suchada Chantrapromma

doi:10.1107/S1600536811006106

. 2011 Feb 23;67(Pt 3):o701–o702. doi: 10.1107/S1600536811006106

3-(4-Bromophenyl)-5-[4-(dimethylamino)phenyl]-4,5-dihydro-1H-pyrazole-1-carbothioamide

Hoong-Kun Fun ^a,^*,^‡, Thitipone Suwunwong ^b, Suchada Chantrapromma ^b,^§

PMCID: PMC3052174 PMID: 21522446

Abstract

The molecule of the title pyrazole derivative, C₁₈H₁₉BrN₄S, is twisted. The central pyrazole ring, which adopts a flattened envelope conformation, is almost coplanar with the 4-bromophenyl ring, whereas it is inclined to the 4-(dimethylamino)phenyl ring making dihedral angles of 1.68 (6) and 85.12 (6)°, respectively. The dihedral angle between the two benzene rings is 86.56 (6)°. The dimethylamino group is slightly twisted from the attached benzene ring [C—C—N—C torsion angles = 8.4 (2) and 8.9 (2)°]. In the crystal, molecules are linked by intermolecular N—H⋯S hydrogen bonds into chains along [2 Inline graphic 0]. The crystal is further stabilized by C—H⋯π interactions.

Related literature

For background to chalcone synthesis and the biological activity of pyrazole derivatives, see: Bekhit et al. (2008 ▶); Ono et al. (2007 ▶); Cottineau et al. (2002 ▶); Gadakh et al. (2010 ▶); Hall et al. (2008 ▶); Hoepping et al. (2007 ▶); Mikhaylichenko et al. (2009 ▶); Park et al. (2005 ▶) Souza et al. (2002 ▶); Xie et al. (2008 ▶). For related structures, see; Chantrapromma et al. (2009 ▶); Suwunwong et al. (2009 ▶). For the stability of the temperature controller used in the data collection, see Cosier & Glazer (1986 ▶). For bond-length data, see: Allen et al. (1987 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₈H₁₉BrN₄S
M _r = 403.34
Triclinic,
a = 6.9153 (1) Å
b = 9.5122 (1) Å
c = 15.1545 (2) Å
α = 72.196 (1)°
β = 80.941 (1)°
γ = 69.845 (1)°
V = 889.48 (2) Å³
Z = 2
Mo Kα radiation
μ = 2.44 mm⁻¹
T = 100 K
0.55 × 0.32 × 0.31 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.349, T _max = 0.520
28456 measured reflections
7823 independent reflections
6784 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.028
wR(F ²) = 0.073
S = 1.05
7823 reflections
227 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.96 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); 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 datablocks global, I. DOI: 10.1107/S1600536811006106/rz2558sup1.cif

e-67-0o701-sup1.cif^{(20.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811006106/rz2558Isup2.hkl

e-67-0o701-Isup2.hkl^{(382.7KB, hkl)}

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

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

Cg1 and Cg2 are the centroids of the C1–C6 and C10–C15 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H1N4⋯S1ⁱ	0.84 (2)	2.54 (2)	3.3679 (11)	170.8 (17)
C5—H5A⋯Cg2ⁱⁱ	0.93	2.72	3.5462 (12)	149
C16—H16B⋯Cg2ⁱⁱⁱ	0.96	2.71	3.6676 (18)	154
C17—H17C⋯Cg1^iv	0.96	2.74	3.5990 (19)	149

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

Acknowledgments

TS thanks the Graduate School, Prince of Songkla University for partial financial support. The authors thank the Prince of Songkla University for financial support through the Crystal Materials Research Unit and also thank Universiti Sains Malaysia for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

The pyrazole moiety is one of the core structures in a number of natural products (Xie et al., 2008). Numerous compounds which contain the pyrazole moiety are known to exhibit a wide range of biological properties such as antihypertensive (Mikhaylichenko et al., 2009), analgesic (Hall et al., 2008), anti-inflammatory (Bekhit et al., 2008), antipyretic (Souza et al., 2002), antimicrobial (Gadakh et al., 2010), hypoglycemic (Cottineau et al., 2002), sedative-hypnotic (Hoepping et al., 2007) and antitumor activities (Park et al., 2005). Our on going research on biological activities of pyrazole derivatives led us to synthesize the title compound by cyclization of the chalcone derivative (Ono et al., 2007) with excess thiosemicarbazide. Herein we report the crystal structure of the title compound.

The molecular structure of the title compound is twisted. The central pyrazole ring adopts a flattened envelope conformation with puckering parameter Q = 0.1775 (11) Å and φ = 75.9 (3)° (Cremer & Pople, 1975), with the slightly puckered C9 atom having the maximum deviation of 0.1120 (11) Å. The pyrazole ring is coplanar with the 4-bromophenyl whereas inclined to the 4-dimethylaminophenyl rings with dihedral angles of 1.68 (6) and 85.12 (6)°, respectively. The dihedral angle between the two phenyl rings being 86.56 (6)°. The dimethylamino group is slightly twisted from the attached benzene ring with the torsion angles C16–N3–C13–C14 = 8.9 (2)° and C17–N3–C13–C12 = 8.4 (2)°. The carbothioamide is slightly twisted from the pyrazole ring as indicated by the torsions angles N4–C18–N2–N1 = 5.51 (14)° and S1–C18–N2–N1 = -172.28 (7)°. The bond distances agree with the literature values (Allen et al., 1987) and are comparable to those observed in related structures (Chantrapromma et al., 2009; Suwunwong et al., 2009).

In the crystal structure (Fig. 2), the molecules are linked by intermolecular N—H···S hydrogen bonds (Table 1) into chains along the [2 1 0] direction. The crystal is further stabilized by C—H···π interactions (Table 1).

Experimental

The title compound was synthesized by dissolving (E)-1-(4-bromophenyl)-3-(4-(dimethylamino)phenyl)prop-2-en-1-one (Ono et al., 2007) (0.33 g, 1.0 mmol) in a solution of KOH (0.06 g, 1.0 mmol) in ethanol (20 ml). An excess thiosemicarbazide (0.14 g, 1.5 mmol) in ethanol (20 ml) was then added, and the reaction mixture was vigorously stirred and refluxed for 7 h. The yellow solid of the title compound obtained after cooling of the reaction mixture was filtered off under vacuum. Pale yellow block-shaped single crystals of the title compound suitable for X-ray structure determination were recrystalized from acetone/ethanol (1:1 v/v) by slow evaporation of the solvent at room temperature after several days. M.p. 481–482 K.