Reaction Steps
To a well stirred solution of 2-(4'-methoxyphenyl)-6-methoxybenzo[b]thiophene (0.305 g, 1.13 mmol) and 4-methoxybenzoyl chloride (0.378 g, 2.22 mmol) in CH2Cl2 (45 ml) was added AlCl3 (0.550 g, 4.12 mmol) portion-wise over a 15 minute period. After 1.3 hours, water was added, and the product was isolated initially by extraction with CH2Cl2 and subsequently by extraction with EtOAc. The organic layers were separately washed with brine and then combined and dried over MgSO4. Purification by flash chromatography (silica gel, 70:30 EtOAc/hexanes) afforded the title compound (0.3576 g, 0.88 mmol, 78%) as a pale yellow solid. Recrystallization (EtOAc/hexanes) afforded a highly pure, crystalline sample with mp 119-120° C. 1H-NMR (CDCl3, 360 MHz): δ=7.77 (d, J=9.0 Hz, 2H, ArH), 7.52 (d, J=8.9 Hz, 1H, ArH), 7.35 (d, J=8.9 Hz, 2H, ArH), 7.31 (d, J=2.3 Hz, 1H, ArH), 6.95 (dd, J=8.9, 2.4 Hz, 1H, ArH), 6.76 (d, J=9.0, 2H, ArH), 6.75 (d, J=8.9, 2H, ArH), 3.87 (s, 3H, --OCH3), 3.79 (s, 3H, --OCH3), 3.74 (s, 3H, --OCH3); 13C-NMR (CDCl3, 90 MHz): δ=193.2, 193.7, 159.7, 157.6, 142.4, 140.0, 134.0, 132.2, 130.5, 130.4, 130.2, 126.0, 124.0, 114.7, 114.0, 113.6, 104.5, 55.6, 55.4, 55.2. HRMS (EI) M+ calcd for C24H20O4S, 404.1082, found 404.1059. Anal. Calcd for C24H20O4S: C, 71.27; H, 4.98; S, 7.93. Found: C, 71.39; H, 4.98; S, 7.90.
