(E)-1-(2,5-Dichloro-3-thien­yl)-3-[4-(dimethyl­amino)phen­yl]prop-2-en-1-one

Grzegorz Dutkiewicz; C S Chidan Kumar; H S Yathirajan; B Narayana; Maciej Kubicki

doi:10.1107/S1600536810014364

. 2010 Apr 24;66(Pt 5):o1139. doi: 10.1107/S1600536810014364

(E)-1-(2,5-Dichloro-3-thienyl)-3-[4-(dimethylamino)phenyl]prop-2-en-1-one

Grzegorz Dutkiewicz ^a,^*, C S Chidan Kumar ^b, H S Yathirajan ^b, B Narayana ^c, Maciej Kubicki ^a

PMCID: PMC2979294 PMID: 21579187

Abstract

In the title compound, C₁₅H₁₃Cl₂NOS, the benzene and thiophene rings make a dihedral angle of 10.8 (1)°. The dimethylamino substituent and the α,β-unsaturated carbonyl group are almost coplanar with respect to the aromatic ring, forming dihedral angles of 4.73 (3)° and 5.0 (2)°, respectively. In the crystal structure, molecules are connected into two-dimensional layers by weak C—H⋯Cl hydrogen bonds and C—Cl⋯O [Cl⋯O = 3.073 (2) Å] interactions. These layers are stacked with short C(methyl)–H⋯π contacts betweeen the layers.

Related literature

For applications of chalcone derivatives, see: Indira et al. (2002 ▶); Sarojini et al. (2006 ▶); Tomar et al. (2007 ▶).

Experimental

Crystal data

C₁₅H₁₃Cl₂NOS
M _r = 326.22
Triclinic,
a = 7.2637 (9) Å
b = 8.1136 (9) Å
c = 13.478 (2) Å
α = 89.011 (9)°
β = 79.71 (1)°
γ = 73.07 (1)°
V = 747.2 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.57 mm⁻¹
T = 295 K
0.6 × 0.3 × 0.3 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with an Eos detector
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.785, T _max = 1.000
8710 measured reflections
3152 independent reflections
2403 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.109
S = 1.10
3152 reflections
184 parameters
H-atom parameters constrained
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: Stereochemical Workstation Operation Manual (Siemens, 1989 ▶) and SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810014364/im2193sup1.cif

e-66-o1139-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810014364/im2193Isup2.hkl

e-66-o1139-Isup2.hkl^{(151.5KB, hkl)}

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

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

Cg is the centroid of the phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C16—H16B⋯Cl5ⁱ	0.96	2.72	3.664 (2)	168
C16—H16A⋯Cgⁱⁱ	0.96	3.01	3.899 (3)	155

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

Acknowledgments

CSC thanks the University of Mysore for research facilities.

supplementary crystallographic information

Comment

Chalcones derivatives are known for their interesting pharmacological activities. Radical quenching properties of the phenolic groups present in many chalcones have raised interest in using the compounds themselves or chalcone rich plant extracts as drugs or food preservatives. Apart from being biologically important compounds, chalcone derivatives show non-linear optical properties with excellent blue light transmittance and good crystallizability (Indira et al., 2002; Sarojini et al., 2006). They provide a necessary configuration to show NLO property with two planar rings connected by a conjugated double bond. Synthesis and antimicrobial evaluation of new chalcones containing a 2,5-dichlorothiophene moiety is reported (Tomar et al., 2007). Here, we report the synthesis and crystal structure of the new chalcone derivative, (2E)-1-(2,5-dichlorothiophen-3-yl)-3-(4-dimethylamino-phenyl)prop-2-en-1-one (I, Scheme 1) .

The molecule as a whole does not deviate significantly from planarity (Fig. 1). Dihedral angles between the constituent planar fragments are relatively small. The two ring planes of the phenyl and thiophene groups make a dihedral angle of 10.8 (1)°. The dimethylamino substituent and the α,β-unsaturated carbonyl moeity are inclined with respect to the phenyl ring plane by 4.73 (3)° and 5.0 (2)°, respectively. The bond lengths pattern within the C(=O)—C=C- fragment shows significant conjugation with shorter formal single bonds compared to formal double bonds that are longer than typical values.

In the crystal structure an intermolecular C–H···Cl hydrogen bond (H···Cl distance 2.72 Å, C–H···Cl angle 168°) and C—Cl···O interactions connect the molecules into approximately planar layers parallel to (101) (Fig. 2). The chlorine oxygen interaction also is almost linear (C2–Cl2···O6 angle of 167.6 (8)°) and relatively short (Cl2···O6 3.073 (2) Å). These layers are stacked on each other showing additional intermolecular C–H···π interactions with H16A···Cg distance of 3.01Å (Cg is the centroid of the phenyl ring).

Experimental

1-(2,5-Dichlorothiophen-3-yl)ethanone (1.95 g, 0.01 mol) was mixed with 4-dimethylamino)-benzaldehyde (1.49 g, 0.01 mol) and dissolved in ethanol (30 ml). 3 ml of KOH (50%) was added to this solution. The reaction mixture was stirred for 6 hours. The resulting crude solid was filtered, washed successively with distilled water and finally recrystallized from ethanol (95%) to give the pure chalcone. Crystals suitable for x-ray diffraction studies were grown by slow evaporation of solution in toluene (M.P.: 358 K).