反应详情

A 1 L round-bottomed flask was charged with compound 10.6 (43.4 g, 84.9 mmol) and EtOH (386 mL). Next, 4 N NaOH (42 mL, 168 mmol) was added dropwise, and the reaction was stirred at room temperature for 30 min. The reaction was then neutralized using 343 mL of 0.5 N HCl, deposited crystals were collected, washed with 2×100 mL of water, and dried in vacuo. Recrystallization from 508 mL of AcOEt/hexanes ({fraction (2/8)}) furnished the title compound 10 (31.1 g) as white crystals. MS APSI m/e: 481 (M−H). 1H NMR (400 MHz) (DMSO-d6) δ 12.98 (1H, brs); 7.65 (2H, d, J=8.7 Hz); 7.58 (1H, s); 7.36-7.29 (3H, m); 7.17 (2H, d, J=8.6 Hz); 6.96 (1H, d, J=8.4 Hz); 6.74 (1H, d, J=8.2 Hz); 5.14 (2H, s); 4.77 (2H, s); 2.21 (3H, s).

1. customwere collected
2. washwashed with 2×100 mL of water
3. customdried in vacuo
4. customRecrystallization from 508 mL of AcOEt/hexanes ({fraction (2/8)})