反应详情

温度

40 °C

1M LiOH aqueous solution (11.72 ml, 11.72 mmol) was added to a solution of 7 (2.00 g, 5.86 mmol) in dioxane (20 mL). The reaction mixture was stirred at 40° C. overnight and was then concentrated under reduced pressure. The residue was dissolved in water. Then concentrated HCl was added to the solution to reach acidic pH to give the precipitation, which was dried by vacuum to afford 8 (1.72 g) as a white solid. 1H NMR (500 MHz, CDCl3): δ6.39 (d, J=16.1 Hz, 1H), 6.71 (d, J=3.6 Hz, 1H), 7.45-7.48 (m, 2H), 7.52 (dd, J=8.7, 1.4 Hz, 1H), 7.55-7.58 (m, 1H), 7.61 (d, J=3.7 Hz, 1H), 7.67-7.72 (m, 2H), 7.89 (d, J=8.9 Hz, 2H), 7.96 (d, J=8.7 Hz, 1H).

1. concentrationwas then concentrated under reduced pressure
2. dissolutionThe residue was dissolved in water
3. additionThen concentrated HCl was added to the solution
4. customto give
5. customthe precipitation, which
6. customwas dried by vacuum