(4-Bromophenyl)(3,6-dimethoxy-2-naphthyl)methanone

In the title compound, C19H15BrO3, the dihedral angle between the naphthalene ring system and the benzene ring is 62.51 (8)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 47.07 (6)° with the naphthalene ring system and 24.20 (10)° with the benzene ring. A weak intermolecular C—H⋯O hydrogen bond exists between the H atom of one methoxy group and the O atom of the other methoxy group in an adjacent molecule. The crystal packing is additionally stabilized by two types of weak intermolecular interactions involving the Br atom, C—H⋯Br and Br⋯O [3.2802 (14) Å].

In the title compound, C 19 H 15 BrO 3 , the dihedral angle between the naphthalene ring system and the benzene ring is 62.51 (8) . The bridging carbonyl C-C( O)-C plane makes dihedral angles of 47.07 (6) with the naphthalene ring system and 24.20 (10) with the benzene ring. A weak intermolecular C-HÁ Á ÁO hydrogen bond exists between the H atom of one methoxy group and the O atom of the other methoxy group in an adjacent molecule. The crystal packing is additionally stabilized by two types of weak intermolecular interactions involving the Br atom, C-HÁ Á ÁBr and BrÁ Á ÁO

Comment
In the course of our study on selective electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene, peri-aroylnaphthalene compounds have proved to be formed regioselectively with the aid of suitable acidic mediator (Okamoto & Yonezawa, 2009).
Furthermore, we also reported the crystal structure analysis of the corresponding β-isomers of 3-aroyl-2,7-dimethoxynaphthalenes such as 2-(4-chlorobenzoyl)-3,6-dimethoxynaphthalene (Nakaema et al., 2008) and (3,6-dimethoxy-2-naphthyl)(4-fluorophenyl)methanone (Watanabe et al., 2010b). In these 3-aroylated naphthalenes, which are generally regarded to be thermodynamically more stable than the corresponding 1-positioned isomeric molecules, the aroyl groups are shown connected to the naphthalene rings in a moderately twisted fashion. As part of our ongoing study on these homologous molecules, the synthesis and crystal structure of the title compound, a 3-monoaroylnaphthalene bearing a bromo group, is discussed in this article. The title compound was prepared by a direct condensation reaction of 2,7-dimethoxynaphthalene with 4-bromobenzoic acid.
The molecular structure of the title molecule is displayed in Fig. 1. The 4-bromophenyl group is bonded twistedly away from the attached naphthalene ring. The dihedral angle between the best planes of the bromophenyl ring (C12-C17) and the naphthalene ring (C1-C10) is 62.51 (8) In the crystal structure, the molecular packing of the title compound is stabilized mainly by van der Waals interactions.
Moreover, there is a C-H···O hydrogen bond between a hydrogen of the 2-methoxy group, which is situated adjacent to the bromophenyl group, and the ethereal oxygen atom of the 7-methoxy group in the neighboring molecule (Table 1, Fig. 2).