反应详情

A mixture of 6-chloro-2-(4-fluoro-1H-indol-2-yl)pyridin-3-ol (10 g, 38 mmol) and metal Sn (23 g, 190 mmol) in CH3CH2OH/concentrated HCl (60 mL/40 mL) was stirred under reflux for 3 h. The mixture was cooled to room temperature and adjusted to pH=7 by saturated NaOH and filtered though a Celite pad. The filtrate was extracted with EtOAc, washed by brine, dried over Na2SO4 and concentrated. The residue was purified by silica gel chromatography (PE:EtOAc=10:1) to get 6-chloro-2-(4-fluoroindolin-2-yl)pyridin-3-ol (8 g, yield: 80%). 1H-NMR (CDCl3, 400 MHz) δ 9.86 (s, 1H), 7.10˜7.20 (m, 3H), 6.33˜6.91 (m, 2H), 5.15˜5.21 (m, 1H), 4.61 (s, 1H), 3.65˜3.71 (m, 1H), 3.04˜3.11 (m, 1H). MS (M+H)+: 265.

1. temperatureunder reflux for 3 h
2. filtrationfiltered though a Celite pad
3. extractionThe filtrate was extracted with EtOAc
4. washwashed by brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated
7. customThe residue was purified by silica gel chromatography (PE:EtOAc=10:1)