(2E)-1-(1,3-Benzodioxol-5-yl)-3-(2-bromo­phen­yl)prop-2-en-1-one

Hongqi Li; R S Rathore; K Prakash Kamath; H S Yathirajan; B Narayana

doi:10.1107/S1600536810015552

. 2010 May 8;66(Pt 6):o1289–o1290. doi: 10.1107/S1600536810015552

(2E)-1-(1,3-Benzodioxol-5-yl)-3-(2-bromophenyl)prop-2-en-1-one

Hongqi Li ^a,^*, R S Rathore ^b, K Prakash Kamath ^c, H S Yathirajan ^d, B Narayana ^e

PMCID: PMC2979485 PMID: 21579387

Abstract

The molecule of the title compound, C₁₆H₁₁BrO₃, is essentially planar with a maximum deviation of 0.178 (4) Å and the configuration of the keto group with respect to the olefinic double bond is typically s-cis. In the crystal structure, intermolecular Br⋯O interactions [3.187 (3)Å] give rise to chains parallel to the b axis. Adjacent chains are further linked along the a axis by C—H⋯π interactions. The crystal studied was a racemic twin with a 0.595 (13):0.405 (13) ratio.

Related literature

For chalcones, see: Di Carlo et al. (1999 ▶); Sarojini et al. (2006 ▶); Yarishkin et al. (2008 ▶). For halogen-bonding interactions, see: Thallapally et al. (2002 ▶); Metrangolo et al. (2005 ▶); Riley et al. (2009 ▶). For related structures, see: Harrison et al. (2006 ▶); Rathore et al. (2006 ▶); Li et al. (2008 ▶); Jasinski et al. (2010 ▶). For racemic twinning, see: Flack (1983 ▶); Flack & Bernardinelli (2000 ▶); Gömez et al. (2010 ▶).

Experimental

Crystal data

C₁₆H₁₁BrO₃
M _r = 331.16
Orthorhombic,
a = 5.0434 (2) Å
b = 12.9354 (4) Å
c = 20.8916 (7) Å
V = 1362.93 (8) Å³
Z = 4
Mo Kα radiation
μ = 3.02 mm⁻¹
T = 296 K
0.53 × 0.19 × 0.16 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.576, T _max = 0.653
17031 measured reflections
2674 independent reflections
2437 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.086
S = 1.06
2674 reflections
182 parameters
H-atom parameters constrained
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.52 e Å⁻³
Absolute structure: Flack (1983 ▶), 1086 Bijvoet pairs
Flack parameter: 0.595 (13)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810015552/rz2432sup1.cif

e-66-o1289-sup1.cif^{(18.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810015552/rz2432Isup2.hkl

e-66-o1289-Isup2.hkl^{(128.9KB, hkl)}

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

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

Cg3 is the centroid of the C10–C15 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C16—H16B⋯Cg3ⁱ	0.97	2.76	3.563 (4)	141

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Symmetry code: (i) Inline graphic .

Acknowledgments

Mangalore University and the Bioinformatics Infrastructure Facility, University of Hyderabad, are gratefully acknowledged. BN thanks UGC–SAP for financial support. RSR thanks the CSIR, New Delhi, for support under the scientist’s pool scheme.

supplementary crystallographic information

Comment

Chalcones possess many interesting biological and pharmacological properties. They are highly reactive substances of varied nature. Recently, it is shown that few of the derivatives are able to block voltage-dependent potassium channels (Yarishkin et al., 2008). Chalcones have been also implicated in organic nonlinear optical materials for their SHG conversion efficiency (Sarojini et al., 2006). The radical quenching property of the phenolic groups present in many chalcones or chalcone-rich plant extracts has led to their use as drugs or food preservatives (Di Carlo et al., 1999). We earlier reported structures of chalcone derivatives (Harrison et al., 2006; Rathore et al., 2006; Jasinski et al., 2010; Li et al., 2008). In continuation of the study, we have synthesized a new chalcone analog, C₁₆H₁₁BrO₃, (I), and discuss its crytal structure herein.

The crystal of (I) studied was racemically twinned in a 0.595 (13):0.405 (13) ratio. Similar racemic twinning in Br-containing compounds was observed by Gömez et al. (2010). The skeleton of (I) is essentially planar possessing two intramolecular short contacts. The bifurcated C1—H7···(Br1, O1) promote planarity of the molecular skeleton (Table 1). The configuration of the keto group with respect to the olefinic double bond is typically s-cis, with the C7—C8—C9—O1 torsion angle of -1.6 (7)° (Rathore et al., 2006).

Crystal packing is characterized by halogen···oxygen interactions between molecules related by 2-fold screw axis, with the Br1 ···O2ⁱ distance of 3.187 (3)Å [symmetry code (i): 0.5+x, 0.5-y, -z] and the C1—Br1···O2 angle of 170.6 (1)°. The Br···O interaction leads to a one-dimensional chain along b axis. Crystal packing is shown in Fig 2. Br···O interactions have previously been employed for crystal engineering purposes (Thallapally et al., 2002). Halogen bonding between halogen atoms (Lewis acid) and neutral or anionic Lewis base, has been subject of great interest in recent years, primarily due to their unique noncovalent bonding characteristics (Metrangolo et al., 2005; Riley et al., 2009). The crystal structure additionally contains a C—H···π short contact, giving rise to an alternate linear pattern along the a axis (Table 1).

Experimental

The title compound was prepared as follows: to a mixture of 1-(1,3-benzodioxol-5-yl)ethanone (1.64 g, 0.01 mol) and 2-bromobenzaldehyde (1.85 g, 0.01 mol) in 30 ml ethanol, 10 ml of 10 % sodium hydroxide solution was added and stirred at 5-10° C for 3 hours. The precipitate formed was collected by filtration and purified by recrystallization from ethanol. Final yield 79%; m.p. 390-392° K. Crystals suitable for X-ray analysis were grown from (1:1 v/v) mixture of toluene and acetone by slow evaporation method. Anal.: calc. for C₁₆H₁₁BrO₃ : C 58.03 , H 3.35; found: C 57.93, H 3.31.