(2E)-3-(6-Meth­oxy­naphthalen-2-yl)-1-[4-(methyl­sulfan­yl)phen­yl]prop-2-en-1-one

Hoong-Kun Fun; Tze Shyang Chia; Mahesh Padaki; Arun M Isloor; A F Ismail

doi:10.1107/S1600536812028930

. 2012 Jun 30;68(Pt 7):o2277–o2278. doi: 10.1107/S1600536812028930

(2E)-3-(6-Methoxynaphthalen-2-yl)-1-[4-(methylsulfanyl)phenyl]prop-2-en-1-one

Hoong-Kun Fun ^a,^*,^‡, Tze Shyang Chia ^a, Mahesh Padaki ^b, Arun M Isloor ^b, A F Ismail ^c

PMCID: PMC3394057 PMID: 22798922

Abstract

The asymmetric unit of the title compound, C₂₁H₁₈O₂S, consists of two crystallographically independent molecules (A and B). The molecules exist in a trans conformation with respect to the central C=C bond. The naphthalene ring system makes dihedral angles of 51.62 (12) (molecule A) and 52.69 (12)° (molecule B) with the benzene ring. In molecule A, the prop-2-en-1-one group forms dihedral angles of 22.84 (15) and 29.02 (12)° with the adjacent naphthalene ring system and benzene ring, respectively, whereas the corresponding angles are 30.04 (12) and 23.33 (12)° in molecule B. In the crystal, molecules are linked by intermolecular C—H⋯O hydrogen bonds into head-to-tail chains along the a axis. The crystal packing also features C—H⋯π interactions. The crystal studied was a pseudo-merohedral twin with twin law (100 0-10 00-1) and a refined component ratio of 0.6103 (16):0.3897 (16).

Related literature

For the preparation and applications of chalcones, see: Mori et al. (2003 ▶); Kumar et al. (2006 ▶); Amir et al. (2008 ▶); Atwal et al. (1990 ▶). For a related structure, see: Kobkeatthawin et al. (2011 ▶). For reference bond lengths, see: Allen et al. (1987 ▶). For stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₂₁H₁₈O₂S
M _r = 334.41
Monoclinic,
a = 18.6118 (14) Å
b = 15.0510 (12) Å
c = 5.9227 (5) Å
β = 90.0005 (15)°
V = 1659.1 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 100 K
0.45 × 0.10 × 0.09 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.913, T _max = 0.982
18668 measured reflections
8757 independent reflections
8185 reflections with I > 2σ(I)
R _int = 0.041

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.136
S = 1.05
8757 reflections
438 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.65 e Å⁻³
Δρ_min = −0.37 e Å⁻³
Absolute structure: Flack (1983 ▶), 3893 Friedel pairs
Flack parameter: 0.24 (8)

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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 datablock(s) global, I. DOI: 10.1107/S1600536812028930/rz2777sup1.cif

e-68-o2277-sup1.cif^{(40.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812028930/rz2777Isup2.hkl

e-68-o2277-Isup2.hkl^{(428.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812028930/rz2777Isup3.cml

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

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

Cg1, Cg2 and Cg3 are the centroids of the C1A/C2A/C7A–C10A, C14A–C19A and C1B/C2B/C7B–C10B rings, respectively

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C20A—H20A⋯O1A ⁱ	0.96	2.44	3.381 (5)	165
C20B—H20D⋯O1B ⁱ	0.96	2.39	3.252 (5)	149
C8A—H8AA⋯Cg1ⁱⁱ	0.93	2.84	3.565 (3)	136
C3B—H3BA⋯Cg2ⁱⁱⁱ	0.93	2.74	3.479 (3)	137
C8B—H8BA⋯Cg3^iv	0.93	2.78	3.494 (3)	134
C20A—H20B⋯Cg3^v	0.96	2.63	3.481 (5)	148

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

Acknowledgments

HKF and TSC thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSC also thanks the Malaysian Government and USM for the award of a research fellowship. AMI is thankful to the Board of Research in Nuclear Sciences, Government of India, for a Young Scientist award. AMI also thanks the Vision Group on Science & Technology, Government of Karnataka, India, for the Best Research Paper award.

supplementary crystallographic information

Comment

Chalcones are unsaturated ketones containing the reactive ketoethylenic group —CO—CH═CH—. These compounds are coloured due to the presence of the chromophore —CO—CH═CH—, and depends on the presence of other auxochromes. Several methods are available for the preparation of chalcones (Mori et al., 2003; Kumar et al., 2006). The most convenient method is the Claisen-Schimdt condensation of equimolar quantities of arylmethylketone with aryl aldehyde in the presence of alcoholic alkali (Amir et al., 2008). Chalcones are used to synthesize several derivatives like cyanopyridines, pyrazolines, isoxazoles and pyrimidines with different heterocyclic ring systems (Atwal et al., 1990). In view of the importance of chalcones, the title compound was synthesized and its crystal structure is reported herein.

The asymmetric unit of the title compound (Fig. 1) consists of two crystallographically independent molecules (A and B). The molecules exist in trans configuration with respect to the central C11═C12 bond. The naphthalene ring system [C1–C10; maximum deviations = 0.037 (3) and 0.041 (3) Å at atom C4 for both molecules] makes dihedral angles of 51.62 (12)° [molecule A] and 52.69 (12)° [molecule B] with the C14–C19 benzene ring. The prop-2-en-1-one group [maximum deviations = 0.0426 (23) Å at atom C13A and 0.0846 (21) Å at atom C13B] forms dihedral angles of 22.84 (15) and 29.02 (12)° with the adjacent naphthalene ring system and benzene ring, respectively in molecules A, whereas the corresponding angles are 30.04 (12) and 23.33 (12)° in molecule B. Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to those found in a related structure (Kobkeatthawin et al., 2011).

In the crystal (Fig. 2), molecules are linked by intermolecular C20A—H20A···O1A and C20B—H20D···O1B hydrogen bonds into chains in head-to-tail fashion, propagating along the a axis. The crystal packing is further stabilized by the C—H···π interactions (Table 1), involving Cg1, Cg2 and Cg3 which are the centroids of C1A/C2A/C7A–C10A, C14A–C19A and C1B/C2B/C7B–C10B rings, respectively.

Experimental

To a thoroughly stirred solution of 6-methoxy-2-naphthaldehyde (0.5 g, 10 mmol) and 1-[4-(methylsulfanyl)phenyl]ethanone (1.66 g, 10 mmol) in 5 ml methanol, 0.5 ml of 40% NaOH solution was added. The reaction mixture was stirred overnight and the solid separated was collected by filtration. The product obtained was recrystallized from methanol. Yield: 2.65 g, 79.3%. M.p. 459–461 K.