Reaction Steps
A mixture of 3,9,10,11-tetramethoxy-5,7-dihydrodibenzo[c,e]oxepin-4-yl trifluoromethanesulfonate (Example 7, 85.2 mg, 0.183 mmol), sodium hydrosulfide hydrate (41.7 mg, 0.743 mmol) and 2-pyrrolidinone (0.4 mL, 0.005 mmol) in a sealed tube was sonicated (Branson 1510, output 70 W) for a period of 10 minutes and then stirred at an oil bath temperature of 90° C. for 1 hour, which afforded a pungent yellow solid. Column chromatography (petroleum ether 60-80°—ethyl acetate 1:1) gave the title compound as a yellow gum (50 mg, 78%); νmax/cm−1 (thin film) 2942, 2867, 2545, 1595, 1486; NMR Spectrum δH (400 MHz, CDCl3) 3.76 (3H, s, OCH3), 3.85 (1H, d, J 12.6 Hz, 5-H or 7-H), 3.92 (3H, s, OCH3), 3.94 (3H, s, OCH3), 3.96 (3H, s, OCH3), 4.05 (1H, d, J 12.6 Hz, 5-H or 7-H), 4.40 (1H, d, J 11.9 Hz, 5-H or 7-H), 5.15 (1H, d, J 11.9 Hz, 5-H or 7-H), 5.86 (1H, s, SH), 6.78 (1H, m, 8-H), 6.94 (1H, d, J 8.5 Hz, 2-H), 7.21 (1H, d, J 8.5 Hz, 1-H); NMR Spectrum δC (100 MHz, CDCl3) 56.44, 56.52, 59.65, 61.23, 61.52, 68.23, 109.17, 110.36, 121.23, 121.49, 126.85, 131.06, 131.56, 143.05, 143.80, 145.96, 151.07, 153.14; m/z (CI, NH3) no molecular ion; Rf (petroleum ether 60-80°—ethyl acetate 1:1) 0.32.
