反应详情

To a solution of 5-chloro-3-pyridinol (20.0 g, 0.154 mol, Aldrich) and KOH (13.0 g, 0.232 mol) in 300 mL of water at 0° C. was added p-nitrobenzenediazonium tetrafluoroborate (36.6 g, 0.154 mol, Aldrich). After 1 hour, 50 mL of glacial acetic acid was added, and the bright red precipitate was filtered and air-dried. Chromatography (silica gel; CH2Cl2/MeOH, 95:5-90:10) afforded the title compound as a bright red solid (28.8 g, 67%): 1H NMR (DMSO-d6, 300 MHz) δ7.14 (d, J=2.4 Hz, 1H), 7.89 (d, J=2.4 Hz, 1H), 8.00 (m, 2H), 8.39 (m, 2H); MS (CI/NH3) m/z: 279, 281 (M+H)+.

1. filtrationthe bright red precipitate was filtered
2. customair-dried