反应详情

4-amino-2,3-difluorophenol (6 g, 41.4 mmol) and potassium tert-butoxide (4.9 g, 43.5 mmol) were suspended in DMAc (200 mL) and stirred at RT for 30 min under Ar atmosphere. 2,4-Dichloropyridine (6.1 g, 41.4 mmol) was added, and the resulting mixture was heated to 70° C. for 8 h. The reaction mixture was filtered, concentrated in vacuo and purified by silica gel chromatography to afford 4-(2-chloro-pyridin-4-yloxy)-2,3-difluoro-phenylamine (7 g, 66% yield). 1H NMR (400 MHz, DMSO-d6): δ 8.27 (d, =6.0 Hz, 1H), 7.05 (s, 1H), 6.95 (m, 1H), 6.92 (m, 1H), 6.62 (m, 1H), 5.60 (s, 2H); MS (ESI) m/z: 257.1 [M+H]+.

1. temperaturethe resulting mixture was heated to 70° C. for 8 h
2. filtrationThe reaction mixture was filtered
3. concentrationconcentrated in vacuo
4. custompurified by silica gel chromatography