反应详情

A suspended mixture of 1′-(diphenylmethyl)-6-fluoro-5-methoxyspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.49 g, 1.09 mmol), triethylsilane (0.23 g, 2.0 mmol) and trifluoroacetic acid (0.57 g, 5.0 mmol) was refluxed under nitrogen for 5 h. The reaction mixture was cooled to ambient temperature and concentrated under reduced pressure. The oily residue was sonicated with hexanes (10 mL) for 10 min and a solid product was filtered off to afford 6-fluoro-5-methoxyspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.29 g, 92%) as a colorless solid: 1H NMR (300 MHz, DMSO-d6) δ 9.28 (s, 1H), 7.37-6.91 (m, 4H), 6.74 (d, J=11.0 Hz, 1H), 6.39 (d, J=8.3 Hz, 1H), 4.82 (ABq, 2H), 3.68 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ180.0, 155.2, 154.9, 154.7, 151.9, 142.9, 142.7, 140.2, 132.1, 129.2, 124.1, 123.6, 122.7, 122.7, 110.4, 109.0, 108.9, 100.0, 99.7, 80.5, 58.8, 57.2; MS (ES+) m/z 285.8 (M+1).

1. temperaturewas refluxed under nitrogen for 5 h
2. concentrationconcentrated under reduced pressure
3. customThe oily residue was sonicated with hexanes (10 mL) for 10 min
4. filtrationa solid product was filtered off