1,2-Bis(benz­yloxy)-1,2-bis­(4-chloro­phen­yl)-3,8-dimeth­oxy­acenaphthene

Teruhisa Takada; Daichi Hijikata; Akiko Okamoto; Hideaki Oike; Noriyuki Yonezawa

doi:10.1107/S1600536811035495

. 2011 Sep 3;67(Pt 10):o2562–o2563. doi: 10.1107/S1600536811035495

1,2-Bis(benzyloxy)-1,2-bis(4-chlorophenyl)-3,8-dimethoxyacenaphthene

Teruhisa Takada ^a, Daichi Hijikata ^a, Akiko Okamoto ^a,^*, Hideaki Oike ^a, Noriyuki Yonezawa ^a

PMCID: PMC3201419 PMID: 22065558

Abstract

In the title compound, C₄₀H₃₂Cl₂O₄, the two chlorobenzene rings are in syn orientations with respect to the naphthalene ring system and make dihedral angles of 57.12 (6) and 85.74 (6)° with it. The benzene rings of the benzyloxy group make dihedral angles of 75.34 (6) and 83.95 (7)°, with the naphthalene ring system. In the crystal, the molecules are linked by intermolecular C—H⋯Cl interactions between the methylene H atoms of the benzyloxy group and the Cl atoms in adjacent molecules. Furthermore, centrosymmetrically related molecules are linked into dimeric units by pairs of C—H⋯π interactions.

Related literature

For the synthesis of aroylated naphthalene compounds via electrophilic aromatic substitution of naphthalene derivatives, see: Okamoto & Yonezawa (2009 ▶). For the structures of closely related compounds, see: Watanabe et al. (2010a ▶,b ▶); Mitsui et al. (2010 ▶); Hijikata et al. (2010 ▶); Nakaema et al. (2007 ▶).

Experimental

Crystal data

C₄₀H₃₂Cl₂O₄
M _r = 647.56
Triclinic,
a = 10.9773 (2) Å
b = 12.6514 (2) Å
c = 12.9171 (2) Å
α = 102.387 (1)°
β = 104.899 (1)°
γ = 103.306 (1)°
V = 1614.04 (5) Å³
Z = 2
Cu Kα radiation
μ = 2.15 mm⁻¹
T = 193 K
0.50 × 0.30 × 0.20 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: numerical (NUMABS; Higashi,1999 ▶) T _min = 0.414, T _max = 0.674
30622 measured reflections
5828 independent reflections
5503 reflections with I > 2σ(I)
R _int = 0.061

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.107
S = 1.06
5828 reflections
418 parameters
H-atom parameters constrained
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811035495/jh2320sup1.cif

e-67-o2562-sup1.cif^{(29.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811035495/jh2320Isup2.hkl

e-67-o2562-Isup2.hkl^{(279.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811035495/jh2320Isup3.cml

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

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

Cg6 is the centroid of the C35–C40 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C34—H34A⋯Cl1ⁱ	0.99	2.66	3.4748 (16)	140
C16—H16⋯Cg6ⁱⁱ	0.95	2.70	3.3962 (16)	131

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

Acknowledgments

The authors would to express their gratitude to Mr Toyokazu Muto, Department of Organic and Polymer Materials Chemistry, Graduate School, Tokyo University of Agriculture & Technology, and Professor Keiichi Noguchi, Instrumentation Analysis Center, Tokyo University of Agriculture & Technology, for their technical advice.

supplementary crystallographic information

Comment

In the course of our study on electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene, peri-aroylnaphthalene compounds have proven to be formed regioselectively with the aid of suitable acidic mediators (Okamoto & Yonezawa, 2009). Recently, we have reported the crystal structures of several 1,8-diaroylated naphthalene homologues exemplified by bis(4-fluorophenyl)(2,7-dimethoxynaphthalene-1,8-diyl)dimethanone (Watanabe et al., 2010a), and bis(4-bromophenyl)(2,7-dimethoxynaphthalene-1,8-diyl)dimethanone (Watanabe et al., 2010b). The aroyl groups at the 1,8-positions of the naphthalene rings in these compounds are twistedly bonded in an almost perpendicular fashion, but the benzene ring moieties of the aroyl groups tilt slightly toward the exo sides of the naphthalene rings. On the other hand, 1,8-bis(4-chlorobenzoyl)-7-methoxynaphthalene-2-ol ethanol monosolvate (Mitsui et al., 2010) and 2,7-dimethoxy-1,8-bis(4-phenoxybenzoyl)naphthalene (Hijikata et al., 2010) have been revealed that the aroyl groups attached to the naphthalene ring are oriented in the same direction, i.e., syn-orientation. As a part of our continuous study on the molecular structures of this kind of homologous molecules, the X-ray crystal structure of the title compound, acenaphthene derivative bearing benzyloxy and 4-chlorophenyl groups, is discussed in this article. The title compound was prepared by Zn-complex-mediated pinacol coupling of 1,8-bis(4-chlorobenzoyl)-2,7-dimethoxynaphthalene (Nakaema et al., 2007), followed by conversion of hydroxy groups to benzyloxy ones. The molecular structure of the title compound is illustrated in Fig. 1. The two intervenient benzene rings, A (C12—C17) and B (C19—C24), are in a syn orientation with respect to the naphthalene ring system (C1—C10), and make the dihedral angles of 57.12 (6) and 85.74 (6)°, respectively, with the naphthalene ring system. Furthermore, the dihedral angles of the two benzene rings in the benzyloxy groups, C (C28—C33) and D (C35—C40), against the naphthalene ring system are 75.34 (6) and 83.95 (7)°, respectively. Besides, the interplanar angle between benzene rings A (C12—C17) and B (C19—C24) is smaller than that between benzene ring C (C28—C33) and D (C35—C40) [31.39 (7) and 84.68 (9)°, respectively].

In the molecular packing, the C—H···Cl interactions between the hydrogen atoms of the methylene moiety and the chloro atoms of the 4-chlorophenyl rings of the adjacent molecules are observed atom along the a axis [C27—H27A···Cl1ⁱ = 2.66 Å](Fig. 2). Furthermore, C—H···π interactions between the hydrogen atom of the benzene ring A and the π-system of the benzene ring D (with centroid Cg6) is also observed (C16—H16···Cg6ⁱⁱ = 2.70 Å; Table 1), resulting in the formation of dimeric units having crystallographic inversion centre (Fig. 3).

Experimental

To a solution of the pinacol compound, 1,2-bis(4-chlorophenyl)-1,2-dihydroxy-3,8-dimethoxyacenaphthene (0.1 mmol, 46 mg) in DMAc (0.1 ml), a mixture of benzyl bromide (0.22 mmol, 34 mg), NaH (0.22 mmol, 48 mg), and tetrabutylammonium iodide (0.01 mmol, 2 mg) was added by portions at r.t. After the reaction mixture was stirred for 3 h, it was poured into ice-cold water (10 ml). The aqueous layer was extracted with CHCl₃ (10 ml ×3). The combined extracts were washed with 2 M aqueous HCl followed by washing with brine. The organic layers thus obtained were dried over anhydrous MgSO₄. The solvent was removed under reduced pressure to give cake (yield 27 mg, 42%). The crude material was purified by recrystallization from CHCl₃/ethanol to give the title compound as colorless platelets (isolated yield, 38%). Spectroscopic Data: ¹H NMR (300 MHz, CDCl₃)δ;7.88, (d, 2H), 7.19–7.26(m, 12H), 6.84 (d, 8H), 4.74–4.84(m, 4H), 3.68(s, 6H); ¹³C NMR(75 MHz, CDCl₃); 154.5, 142.0, 140.3, 140.0, 132.1, 128.9, 128.9, 127.9, 127.3, 126.8, 126.7, 122.4, 122.3, 113.6, 96.7, 69.1, 55,7; IR (KBr);1623, 1502, 1259 cm^-1; Anal. Calcd for C₄₀H₃₂Cl₂O₄; C, 74.19; H, 4.98. Found: C, 74.176; H, 5.160%; m.p.=203.0–204.0 K.