反应详情

A suspension of 2-aminofluoren-9-one (400 mg, 2.05 mmol; Aldrich) and anhydrous sodium sulfate (3.0 g, 21 mmol; EM Science) in acetic acid (10 mL) was stirred for 15 min and then treated with sodium triacetoxyborohydride (1.3 g, 6.13 mmol; Aldrich). After stirring overnight, the reaction mixture was basified with saturated aqueous Na2CO3 and extracted with EtOAc (3×). The combined organic phases were concentrated under vacuum and purified by flash chromatography (80 g silica gel, 1-16% gradient of NH4OH-MeOH (1:10) in CH2Cl2) to afford the title compound (492 mg, 1.62 mmol; 79% yield): 1H NMR (300 MHz, CD3OD) δ ppm 7.35-7.47 (m, 3H), 7.33 (d, J=8 Hz, 1H), 7.11 (td, J=7, 2 Hz, 1H), 6.86 (d, J=2 Hz, 1H), 6.70 (dd, J=8, 2 Hz, 1H), 3.57-3.67 (m, 1H), 3.32-3.40 (m, 1H), 2.74-3.00 (m, 4H), 2.60 (ddd, J=14, 5, 1 Hz, 1H), 1.67-2.06 (m, 4H), 1.41-1.55 (m, 1H); MS (DCl/NH3) m/z 305 (M+H)+.

1. stirringAfter stirring overnight
2. extractionextracted with EtOAc (3×)
3. concentrationThe combined organic phases were concentrated under vacuum
4. custompurified by flash chromatography (80 g silica gel, 1-16% gradient of NH4OH-MeOH (1:10) in CH2Cl2)