[2,7-Dimethoxy-8-(4-methoxybenzoyl)naphthalen-1-yl](4-methoxyphenyl)methanone chloroform monosolvate

In the title compound, C28H24O6·CHCl3, the two 4-methoxybenzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost antiparallel, the benzene rings making a dihedral angle of 25.76 (7)°. The naphthalene ring system makes dihedral angles of 72.51 (7) and 73.33 (7)° with the benzene rings. In the crystal, the naphthalene molecules are linked by C—H⋯O interactions, forming a helical chain along the b-axis direction. A C—H⋯Cl interaction is also observed between the aroylated naphthalene and chloroform molecules. The chloroform molecule is disordered over two positions with site occupancies of 0.478 (5) and 0.522 (5).

The molecular structure of the title compound is displayed in Fig. 1. Two 4-methoxybenzoyl groups are situated in the anti-orientation. The dihedral angle between the best planes of the two phenyl rings is 25.76 (7)°. The dihedral angles between the best planes of the two 4-methoxyphenyl rings and the naphthalene ring are 72.51 (7) and 73.33 (7)°, respectively. The dihedral angles between the naphthalene ring system and the bridging ketonic carbonyl C-C(═O)-C planes [65.95 (8) and 68.67 (6)°] are larger than those between the phenyl rings and the bridging carbonyl planes [8.40 (8) and 5.49 (7)°].
Experimental 4-Methoxylbenzoyl chloride (6.60 mmol, 1.13 g), titanium chloride (19.8 mmol, 3.76 g) and methylene chloride (5.00 ml) were placed into a 50 ml flask, followed by stirring at room temperature. To the reaction mixture thus obtained, 2,7dimethoxynaphthalene (2.00 mmol, 376 mg) was added. The reaction mixture was poured into ice-cold water (100 ml) after it had been stirred for 6 h at room temperature. The aqueous layer was extracted with CHCl 3 (20 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 MgSO 4 . The solvent was removed under reduced pressure to give a cake. The crude product was purified by recrystallization from hexane and CHCl 3 (yield 45%). Colorless platelet single crystals suitable for X-ray  24, 56.49, 111.24, 113.20, 121.89, 125.54, 129.62, 131.39, 131.71, 132.05, 155.93, 163.03, 194.98

Refinement
All H atoms were found in a difference map and were subsequently refined as riding atoms, with C-H = 0.95 (aromatic), 0.98 (methyl) and 1.00 (chloroform) Å, and with U iso (H) = 1.2U eq (C).

Figure 1
Molecular structure with the atom-labeling scheme and displacement ellipsoids drawn at the 50% probability level.
Hydrogen atoms are shown as small spheres of arbitrary radius.      Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.