(E)-3-[4-(Hex­yloxy)phen­yl]-1-(2-hydroxy­phen­yl)prop-2-en-1-one

Zainab Ngaini; Siti Muhaini Haris Fadzillah; Hasnain Hussain; Ibrahim Abdul Razak; Hoong-Kun Fun

doi:10.1107/S1600536809017577

. 2009 May 14;65(Pt 6):o1301–o1302. doi: 10.1107/S1600536809017577

(E)-3-[4-(Hexyloxy)phenyl]-1-(2-hydroxyphenyl)prop-2-en-1-one

Zainab Ngaini ^a, Siti Muhaini Haris Fadzillah ^a, Hasnain Hussain ^b, Ibrahim Abdul Razak ^c,^*,^‡, Hoong-Kun Fun ^c,^§

PMCID: PMC2969631 PMID: 21583159

Abstract

In the title compound, C₂₁H₂₄O₃, the conformation of the enone group is s–cis. The benzene rings are inclined at an angle of 7.9 (1)°. The alkoxy tail is planar, with a maximum deviation from the least-squares plane of 0.009 (2) Å, and adopts a trans conformation throughout. An intramolecular O—H⋯O interaction between the keto and hydroxy groups forms S(6) ring motifs. In the crystal, molecules are arranged in a head-to-tail manner down the a axis and are subsequently stacked along the b axis, forming molecular sheets parallel to the ab plane. The crystal structure is further stabilized by weak C—H⋯π interactions and short C⋯O [3.376 (2) Å] contacts.

Related literature

For the biological properties of chalcone derivatives, see: Bhat et al. (2005 ▶); Xue et al. (2004 ▶); Zhao et al. (2005 ▶); Lee et al. (2006 ▶). For related structures, see: Razak, Fun, Ngaini, Rahman & Hussain (2009 ▶); Razak, Fun, Ngaini, Fadzillah & Hussain (2009a ▶,b ▶); Ngaini, Fadzillah et al. (2009 ▶); Ngaini, Rahman et al. (2009 ▶). For details of hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₁H₂₄O₃
M _r = 324.40
Monoclinic,
a = 19.6443 (5) Å
b = 7.1966 (2) Å
c = 12.6520 (3) Å
β = 106.438 (2)°
V = 1715.53 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.47 × 0.12 × 0.04 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.962, T _max = 0.997
20873 measured reflections
5025 independent reflections
2783 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.070
wR(F ²) = 0.190
S = 1.05
5025 reflections
222 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.29 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/S1600536809017577/sj2623sup1.cif

e-65-o1301-sup1.cif^{(20.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809017577/sj2623Isup2.hkl

e-65-o1301-Isup2.hkl^{(246.1KB, hkl)}

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
O1—H1O1⋯O2	0.90 (3)	1.68 (3)	2.507 (2)	152 (2)
C20—H20A⋯Cg1ⁱ	0.97	2.84	3.657 (2)	142
C20—H20B⋯Cg1ⁱⁱ	0.97	2.78	3.637 (2)	147

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 is the centroid of the C1-C6 ring.

Acknowledgments

HKF and IAR thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312 and for the Research University Golden Goose grant No.1001/PFIZIK/811012. ZN and HH thank Universiti Malaysia Sarawak for the Geran Penyelidikan Dana Khas Inovasi, grant No. DI/01/2007(01). SMHF thanks the Malaysian Government and Universiti Malaysia Sarawak for providing a scholarship for postgraduate studies.

supplementary crystallographic information

Comment

The biological properties of chalcones derivatives, such as their anticancer (Bhat et al., 2005), antimalarial (Xue et al., 2004), antiangiogenic and antitumour (Lee et al., 2006) and antiplatelet (Zhao et al., 2005) activities, have been extensively reported. Synthetic and naturally occurring chalcones are of interest and have been widely studied and developed as one of the pharmaceutically important molecules. As part of our studies, we have synthesized the title chalcone derivative, (I). Its antibacterial activity was tested against E. coli ATCC 8739 and the compound demonstrated antimicrobial activity. In this paper, we report the crystal structure of the title compound.

The bond lengths observed in the title compound (Fig.1) are comparable with those reported by Allen et al. (1987). The enone (O2/C7—C9) moiety adopts s-cis conformation with a O2—C7—C8—C9 torsion angle of -3.6 (3)°. The mean plane through the enone moiety makes dihedral angles of 0.89 (1)° and 7.9 (1)° with the C1—C6 and C10—C15 benzene rings, respectively. The dihedral angle between the two benzene rings is 7.9 (1)°.

The slight opening of the C1—C6—C7 (123.4 (2)°) and C6—C7—C8 (121.1 (2)°) angles is the result of the short H1A···H8A (2.15 Å) contact whereas close interatomic contact between H8A and H15A (2.36 Å) widened the C8—C9—C10 and C9—C10—C15 angles to 129.2 (2)° and 124.1 (2)°, respectively. Likewise, strain induced by short H12A···H16A (2.39 Å) and H12A···H16B (2.33 Å) contacts resulted in the opening of the O3—C13—C12 (125.1 (2)°) angle. Similar features were also reported in related structures (Razak, Fun, Ngaini, Rahman et al., 2009; Razak, Fun, Ngaini, Fadzillah & Hussain, 2009a,b; Ngaini, Fadzillah et al., 2009; Ngaini, Rahman et al., 2009).

The zigzag alkoxyl tail adopts an all-trans conformation with the largest deviation from the ideal value being -179.3 (2)° for C17—C18—C19—C20 torsion angle. The alkoxyl chain is planar with the maximum deviation from the least-squares plane of 0.009 (2)Å at C18. The zigzag plane makes a dihedral angle of 2.2 (1)° with the attached benzene ring.

The keto and hydroxy groups in the molecule form an intramolecular O1—H1O1···O2 interaction (Table 1) generating a ring of graph-set motif S(6) (Bernstein et al., 1995). In the crystal structure, the molecules are arranged into a head-to-tail manner down the a axis (Fig. 2). Molecules are subsequently stacked along the b axis, forming molecular sheets parallel to the ab plane. In the absence of conventional hydrogen bonds, the crystal packing is strengthened by the presence of weak C—H···π interactions between atom C20 of the alkoxyl tail and the C1—C6 benzene ring (Table 1). There is also a short C···O (x, 1.5-y, 0.5+z ) [3.376 (2)Å] contact.

Experimental

A mixture of 2-hydroxyacetophenone (2.72 ml, 20 mmol) and 4-hexyloxybenzaldehyde (4.12 ml, 20 mmol) and KOH (4.04 g, 72 mmol) in 60 ml of methanol was heated at reflux for 24 h. The reaction was cooled to room temperature and acidified with cold diluted HCl (2 M). The resulting precipitate was filtered, washed and dried. After redissolving in hexane, followed by few days of slow evaporation, crystals were collected.