Reaction Steps
To a well-stirred solution of 2-(4'-methoxyphenyl)-6-methoxybenzo[b]thiophene (0.500 g, 1.85 mmol) and 2,6-dimethoxybenzoyl chloride (1.11 g, 5.56 mmol) in CH2Cl2 (40 mL) was added AlCl3 (0.986 g, 7.40 mmol) portion-wise over a 15 minute period. After 6 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, 60:40 EtOAc/hexane) afforded the title compound (0.484 g, 1.11 mmol, 60%) as an off-white solid. Recrystallization (hexane/ethanol) afforded a highly pure, crystalline sample with mp 146-152° C.: 1H-NMR (CDCl3, 360 Mhz): δ=8.54 (dd, J=9.1, 0.3 Hz, 1H, ArH), 7.25 (d, J=2.1 Hz, 1H, ArH), 7.12 (d, J=8.8 Hz, 2H, ArH), 7.10 (dd, J=9.0, 2.5 Hz, 1H, ArH), 6.98 (t, J=8.4 Hz, 1H, ArH), 6.58 (d, J=8.8 Hz, 2H, ArH), 6.20 (d, J=8.4 Hz, 2H, ArH), 3.88 (s, 3H, --OCH3), 3.73 (s, 3H, --OCH3), 3.60 (s, 6H, --OCH3); 13C-NMR (CDCl3, 90 Mhz): δ=190.3, 159.5, 157.3, 157.3, 151.3, 139.3, 132.9, 131.9, 130.8, 130.5, 126.4, 125.7, 120.3 115.0, 112.6, 103.9, 103.6, 55.6, 55.5, 55.3. HRMS (EI) M+ calcd for C25H22O5S 434.1188, found 434.1188. Anal. Calcd for C25H22O5S: C, 69.11; H, 5.10; S,7.38. Found: C, 69.19; H, 5.18; S, 7.28.
