(3,5-Dimethyl­phen­yl)[8-(3,5-dimethyl­benzo­yl)-2,7-dimeth­oxy­naphthalen-1-yl]methanone

Toyokazu Muto; Kosuke Sasagawa; Akiko Okamoto; Hideaki Oike; Noriyuki Yonezawa

doi:10.1107/S1600536812012202

. 2012 Mar 28;68(Pt 4):o1200. doi: 10.1107/S1600536812012202

(3,5-Dimethylphenyl)[8-(3,5-dimethylbenzoyl)-2,7-dimethoxynaphthalen-1-yl]methanone

Toyokazu Muto ^a, Kosuke Sasagawa ^a, Akiko Okamoto ^a,^*, Hideaki Oike ^a, Noriyuki Yonezawa ^a

PMCID: PMC3344137 PMID: 22606140

Abstract

In the title molecule, C₃₀H₂₈O₄, the interplanar angle between the two benzene rings of the 3,5-dimethylbenzoyl groups is 50.35 (7)°. The dihedral angles between the two benzene rings and the naphthalene ring system are 81.87 (6) and 83.55 (6)°. In addition, the conformations of the pairs of methyl groups and their counterparts differ from each other though their environment is very similar. In the crystal, weak C—H⋯O interactions occur.

Related literature

For electrophilic aromatic substitution of naphthalene derivatives, see: Okamoto & Yonezawa (2009 ▶); Okamoto et al. (2011 ▶). For the structures of closely related compounds, see: Muto et al. (2010 ▶, 2011a ▶,b ▶; 2012 ▶).

Experimental

Crystal data

C₃₀H₂₈O₄
M _r = 452.52
Monoclinic,
a = 19.4659 (3) Å
b = 8.27808 (10) Å
c = 15.8244 (2) Å
β = 110.69°
V = 2385.46 (6) Å³
Z = 4
Cu Kα radiation
μ = 0.66 mm⁻¹
T = 193 K
0.50 × 0.20 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: numerical (NUMABS; Higashi, 1999 ▶) T _min = 0.734, T _max = 0.937
43008 measured reflections
4360 independent reflections
3884 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.118
S = 1.08
4360 reflections
314 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.16 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/S1600536812012202/fb2243sup1.cif

e-68-o1200-sup1.cif^{(31.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812012202/fb2243Isup2.hkl

e-68-o1200-Isup2.hkl^{(213.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812012202/fb2243Isup3.cml

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
C7—H7⋯O1ⁱ	0.95	2.55	3.1332 (17)	120
C25—H25B⋯O2ⁱⁱ	0.98	2.41	3.170 (2)	134
C26—H26A⋯O1ⁱ	0.98	2.59	3.475 (2)	150

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

Acknowledgments

The authors express their gratitude to Master Daichi Hijikata, Department of Organic and Polymer Materials Chemistry, Graduate School, Tokyo University of Agriculture and Technology, and Professor Keiichi Noguchi, Instrumentation Analysis Center, Tokyo University of Agriculture and 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; Okamoto, Mitsui et al., 2011). We have recently reported crystal structures of several 1,8-diaroylated naphthalene analogues exemplified by 1,8-bis(4-methylbenzoyl)-2,7-dimethoxynaphthalene (Muto et al., 2010) and 1,8-bis(2,4,6-trimethylbenzoyl)-2,7-dimethoxynaphthalene (Muto et al., 2012). In these compounds, the aroyl groups at the 1,8-positions of the naphthalene rings contain almost 90°. In addition, crystal structures of 1-monoaroylated naphthalene derivatives and the β-isomers of 3-monoaroylated derivatives have been also determined such as (2,7-dimethoxynaphthalen-1-yl)(2,4,6-trimethylphenyl)methanone (Muto et al., 2011a) and (3,6-dimethoxynaphthalen-2-yl)(2,4,6-trimethylphenyl)methanone (Muto et al., 2011b).

As a part of our continuing study on the molecular structures of these homologous molecules, the crystal structure of title compound, peri-aroylnaphthalene bearing two methyl groups at 3,5-positions on the phenyl group, is discussed in this article.

The title molecule is displayed in Fig. 1. Two 3,5-dimethylphenyl groups are out of the plane of the naphthalene ring. The interplanar angle between the best planes of the two phenyl rings (C12\C17 and C19\C24) is 50.35 (7)°. On the other hand, the two interplanar angles between the best planes of the 3,5-dimethylphenyl rings and the naphthalene ring are 81.87 (6) and 83.55 (6)°, respectively.

The torsion angles between the carbonyl groups and the naphthalene ring are 113.52 (15)° [C2\C1\C11\O1] and 102.95 (16)° [C8\C9\C18\O2], furthermore those between the carbonyl groups and 3,5-dimethylphenyl groups are 153.91 (13)° [O1\C11\C12\C13] and 164.07 (13)° [O2\C18\C19\C24].

In the crystal structure, the molecular packing of the title compound is stabilized mainly by van der Waals interactions. In addition, the crystal packing is stabilized by three different C—H···O interactions: 1) C7—H7···O1ⁱ (Fig. 2 and Table 1). This interaction is directed along the b axis. 2) C25—H25b···O2ⁱⁱ (Fig. 3 and Table 1). This interaction is directed along the c axis. 3) C26—H26a···O1ⁱ (Fig. 2 and Table 1). This interaction is directed along the b axis.

Experimental

3,5-dimethylbenzoyl chloride (1.50 mmol, 253 mg), titanium chloride (1.50 mmol, 285 mg) and methylene chloride (1.25 ml) were placed into a 10 ml flask, followed by stirring at room temperature. To the reaction mixture thus obtained, 2,7-dimethoxynaphthalene (0.50 mmol, 94.1 mg) was added. The reaction mixture was poured into ice-cold water (30 ml) after it had been stirred for 6 h at room temperature. The aqueous layer was extracted with CHCl₃ (10 ml × 3). The combined extracts were washed with 2 M aqueous NaOH followed by washing with brine. The extracts thus obtained were dried over anhydrous MgSO₄. The solvent was removed under reduced pressure to give a cake. The crude product was purified by recrystallization from hexane and CHCl₃ (yield 62%). Colourless platelet single crystals suitable for X-ray diffraction were obtained (the average size: 0.8 × 0.4 × 0.1 mm) by repeated crystallization from hexane/CHCl₃ mixtures (4:1 v/v).

¹H NMR δ (300 MHz, CDCl₃); 2.24 (12H, s), 3.69 (6H, s), 7.05 (2H, s), 7.21 (2H, d, J = 9.0 Hz), 7.26 (4H, s), 7.95 (2H, d, J = 9.3 Hz) p.p.m..

¹³C NMR δ (75 MHz, CDCl₃); 21.19, 56.53, 111.40, 121.94, 124.53, 125.54, 126.99, 131.86, 134.52, 137.19, 138.56, 156.26, 196.94 p.p.m..

IR (KBr); 1656 (C=O), 1610, 1511, 1459 (Ar, naphthalene), 1267 (=C—O—C) cm^-1.

High-resolution mass spectra (m/z); [M + Na]⁺ Calcd for C₃₀H₂₈O₄Na, 475.1885; found, 475.1851.

m.p. = 576–580 K.