2-[(E)-4-Meth­oxy­benzyl­idene]-1,2,3,4-tetra­hydro­naphthalen-1-one

Abdullah M Asiri; Hassan M Faidallah; Mohie E M Zayed; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S160053681202805X

. 2012 Jun 23;68(Pt 7):o2190. doi: 10.1107/S160053681202805X

2-[(E)-4-Methoxybenzylidene]-1,2,3,4-tetrahydronaphthalen-1-one

Abdullah M Asiri ^a,^‡, Hassan M Faidallah ^a, Mohie E M Zayed ^a, Seik Weng Ng ^b, Edward R T Tiekink ^b,^*

PMCID: PMC3393990 PMID: 22798855

Abstract

Two independent molecules (A and B) comprise the asymmetric unit of the title compound, C₁₈H₁₆O₂. Molecule B is virtually superimposable upon A. Minor differences are noted in the dihedral angles between the terminal benzene rings of 56.03 (10) and 54.62 (10)°, and in the orientations of methoxy groups with respect to the benzene rings to which they are attached [C—O—C—C torsion angles = 169.11 (19) and −172.37 (18)°]. The cyclohexene ring of each fused ring system has a screw-boat conformation. In the crystal, C—H⋯π interactions assemble molecules into a supramolecular array in the ab plane.

Related literature

For the activity of related species developed for the treatment of Chagas disease, see: Vera-DiVaio et al. (2009 ▶). For the structure of the 2-methoxy derivative, see: Dimmock et al. (2002 ▶). For conformational analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₈H₁₆O₂
M _r = 264.31
Monoclinic,
a = 6.8289 (4) Å
b = 14.7444 (8) Å
c = 26.7258 (14) Å
β = 93.757 (5)°
V = 2685.2 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.40 × 0.20 × 0.10 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.766, T _max = 1.000
18691 measured reflections
6195 independent reflections
3813 reflections with I > 2σ(I)
R _int = 0.054

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.187
S = 0.99
6195 reflections
361 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681202805X/bt5948sup1.cif

e-68-o2190-sup1.cif^{(26.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681202805X/bt5948Isup2.hkl

e-68-o2190-Isup2.hkl^{(303.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S160053681202805X/bt5948Isup3.cml

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

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

Cg1–Cg3 are the centroids of the C20–C25, C2–C7 and C12–C17 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13⋯Cg1ⁱ	0.95	2.70	3.486 (2)	140
C21—H21⋯Cg2ⁱⁱ	0.95	2.97	3.595 (2)	124
C31—H31⋯Cg2ⁱⁱⁱ	0.95	2.64	3.411 (2)	139
C36—H36B⋯Cg3	0.98	2.88	3.592 (2)	131

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

Acknowledgments

The authors are grateful to King Abdulaziz University for providing research facilities. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

The crystal structure of the title compound, 2-(4-methoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one (I), was investigated owing to its relationship to some active compounds developed for the treatment of Chagas disease (Vera-DiVaio et al., 2009).

Two independent molecules comprise the asymmetric unit of (I), Fig. 1. The inverted structure of the O3-containing molecule is virtually super-imposable upon the O1-containing molecule, Fig. 2. The cyclohexene ring of each fused ring system has a screw boat conformation (Cremer & Pople, 1975). A difference between the molecules is seen in the dihedral angles between the terminal benzene rings of 56.03 (10) and 54.62 (10)°, respectively. The methoxy groups are co-planar with the benzene rings to which they are attached as seen in the C18—O2—C15—C14 and C36—O4—C33—C32 torsion angles of 169.11 (19) and -172.37 (18)°, respectively. The conformation about each ethylene bond is E. The overall molecular conformation observed for the independent molecules of (I) resembles that seen in the 2-methoxy derivative (Dimmock et al., 2002).

The presence of C—H···π interactions link molecules into a supramolecular array in the ab plane in the crystal structure of (I), Fig. 3 and Table 1. Layers stack along the c axis with no specific interactions between them (Fig. 4).

Experimental

A solution of the 4-methoxybenzaldehyde (1.3 g, 0.01 M) in ethanol (20 ml) was added to a stirred solution of 1-tetralone (1.46 g,0.01 M) in ethanolic KOH (20 ml, 20%), and stirring was maintained at room temperature for 6 h. The reaction mixture was then poured onto water (200 ml) and set aside overnight. The precipitated solid product was collected by filtration, washed with water, dried and recrystallized from ethanol. Yield: 92%.