反应详情

温度

60 °C

Ethylenediamine (0.090 mL, 1.35 mmol) and 1M solution of TBAF in THF (2.70 mL, 2.70 mmol) were added to a solution of 52 (0.300 g, 0.90 mmol) in THF (5 mL). The mixture was stirred at 60° C. for 6 hours. More 1.0 M TBAF solution (1.80 ml, 1.80 mmol) was added and stirring was continued at 60° C. for 42 hours. The mixture was cooled, and poured into saturated aqueous NaHCO3 solution and extracted with AcOEt. The organic layer was washed with brine, dried (MgSO4), and concentrated to afford a tan solid. The solid was recrystallized from AcOEt to afford 53 (0.065 g) as a pale yellow crystalline solid. The mother liquors were concentrated and successively purified by means of SGC with AcOEt: MeOH as eluent and preparative TLC with CH2Cl2:MeOH as eluent to afford additional 53 (0.060 g, total yield: 0.125 g, 68%) as a pale yellow solid. 1H NMR (400 MHz, CDCl3) δ 3.05-3.09 (m, 4H), 3.83-3.87 (m, 4H), 6.36 (dd, J=0.35, 0.20 Hz, 1H), 7.22 (dd, J=0.33, 0.25 Hz, 1H), 7.45 (d, J=0.25 Hz, 1H), 8.07 (d, J=0.25 Hz, 1H), 8.97 (bs, 1H).

1. stirringstirring
2. waitwas continued at 60° C. for 42 hours
3. temperatureThe mixture was cooled
4. extractionextracted with AcOEt
5. washThe organic layer was washed with brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated
8. customto afford a tan solid
9. customThe solid was recrystallized from AcOEt