反应详情

Intermediate 19A (0.75 g, 2.15 mmol) was dissolved in a 4.0 M solution of HCl in MeOH (20 mL) and the reaction mixture was stirred at RT over night. The mixture was concentrated and the residue was dissolved in water. The solution was basified to pH=10 with aqueous NaOH (1.0 M) and extracted with DCM (4×30 mL). The combined organic phases were filtered through a phase separator and the solvent was removed by evaporation. There was obtained 0.43 g (72%) of 19B as a colorless oil. 1H NMR (500 MHz, CDCl3): δ 1.71-1.83 (m, 4H), 2.33 (s, 3H), 2.43-2.55 (m, 4H), 3.52 (s, 2H), 3.73-3.85 (m, 2H), 3.85-3.96 (m, 2H), 4.91-5.03 (m, 1H), 6.52 (d, 1H), 6.57 (s, 1H), 7.17 (d, 1H).

1. concentrationThe mixture was concentrated
2. dissolutionthe residue was dissolved in water
3. extractionextracted with DCM (4×30 mL)
4. filtrationThe combined organic phases were filtered through a phase separator
5. customthe solvent was removed by evaporation