2-(4-Chloro­benzo­yl)-3,6-dimethoxy­naphthalene

Kosuke Nakaema; Akiko Okamoto; Masahiro Imaizumi; Keiichi Noguchi; Noriyuki Yonezawa

doi:10.1107/S1600536808004704

. 2008 Feb 22;64(Pt 3):o612. doi: 10.1107/S1600536808004704

2-(4-Chlorobenzoyl)-3,6-dimethoxynaphthalene

Kosuke Nakaema ^a, Akiko Okamoto ^a, Masahiro Imaizumi ^b, Keiichi Noguchi ^c, Noriyuki Yonezawa ^a,^*

PMCID: PMC2960802 PMID: 21201947

Abstract

In the title compound, C₁₉H₁₅ClO₃, the interplanar angle between the naphthalene and benzene ring systems is 62.67 (6)°. The carbonyl group is twisted from both ring planes, with torsion angles of −44.9 (2)° with respect to the naphthalene ring and −26.7 (2)° with respect to the phenylene ring. There is an intermolecular hydrogen bond between an H atom of one methoxy group and the O atom of the second methoxy group, forming chains along the ac diagonal.

Related literature

For related literature, see: Ahn et al. (2003 ▶); Allen et al. (1998 ▶); Chen et al. (2005 ▶); Crasto & Stevens (1998 ▶, 2002 ▶); Lorenzetti et al. (2005 ▶); Nakaema et al. (2007 ▶); Su et al. (2004 ▶); Wang & Guen (1995 ▶).

Experimental

Crystal data

C₁₉H₁₅ClO₃
M _r = 326.76
Monoclinic,
a = 8.1894 (5) Å
b = 20.5251 (13) Å
c = 9.9098 (7) Å
β = 106.358 (4)°
V = 1598.29 (18) Å³
Z = 4
Cu Kα radiation
μ = 2.22 mm⁻¹
T = 296 K
0.50 × 0.25 × 0.10 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: numerical (NUMABS; Higashi, 1999 ▶) T _min = 0.458, T _max = 0.801
30087 measured reflections
2917 independent reflections
2652 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.100
S = 1.07
2917 reflections
211 parameters
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.28 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: SIR92 (Altomare et al., 1994 ▶); 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 datablocks I, global. DOI: 10.1107/S1600536808004704/fl2189sup1.cif

e-64-0o612-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808004704/fl2189Isup2.hkl

e-64-0o612-Isup2.hkl^{(140.3KB, 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
C18—H18C⋯O3ⁱ	0.96	2.51	3.460 (2)	171

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was partially supported by the Ogasawara Foundation for the Promotion of Science & Engineering, Tokyo, Japan.

supplementary crystallographic information

Comment

Naphthalene derivatives, such as 1,5-disubstituted and 2,6-disubstituted naphthalenes, have been used widely as key building blocks of functional organic compounds such as liquid crystals and electric materials (Su et al., 2004; Ahn et al., 2003; Lorenzetti et al., 2005; Chen et al., 2005). Recently, 1,8-disubstituted naphthalenes have received much attention as unique structured aromatic core compounds, exemplified by dendron cores and supramolecular building blocks (Wang & Guen, 1995; Allen et al., 1998; Crasto & Stevens, 1998, 2002).

In this paper, the structural characteristics of the title compound, which is one of the products of electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene, is reported and discussed. The authors have recently reported the crystal structure of the 1,8-diaroylated derivative of 2,7-dimethoxynaphthalene as the product of regioselective electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene with 4-chlorobenzoic acid (Nakaema et al., 2007). As 3-substituted naphthalene compounds are generally regarded to be thermodynamically more stable than the corresponding 1-positioned isomeric molecules, the title molecule is of interest from both the stereochemical features of its conformation and the thermodynamic aspects of its molecular structure.

An ORTEPIII (Burnett & Johnson, 1996) plot of the title molecule, (I), is displayed in Fig. 1. The 4-chlorobenzoyl group is twisted away from the attached naphthalene ring. The interplanar angle between the best planes of the chlorophenyl ring and the naphthalene ring is 62.67 (6)°. The torsion angle between the carbonyl group and the naphthalene ring is relatively large [C4—C3—C11—O1 = -44.9 (2)°] and that between 4-chlorophenyl group and carbonyl group is rather small [O1—C11—C12—C13 = -26.7 (2)°].

The crystal packing is stabilized mainly by van der Waals interactions. In addition, there is a C—H···O hydrogen bond between a hydrogen of the 2-methoxy group which is situated adjacent to the chlorobenzoyl group, and the ethereal oxygen of the 7-methoxy group in a neighboring molecule that could also contribute the stabilization of the crystal packing (Table 1, Figure 2).

Experimental

The title compound was prepared by electrophilic aromatic aroylation reaction of 2,7-dimethoxynaphthalene with 4-chlorobenzoic acid. Yellow single crystals suitable for X-ray diffraction were obtained by recrystallization from ethanol and ethyl acetate.