反应详情

Potassium tert-butoxide (2.4 g, 22 mmol) was added to a solution of 4-amino-2,6-difluorophenol (2.9 g, 20 mmol) in N,N-dimethyl-acetamide (50 mL) and the mixture was stirred at RT under nitrogen for 0.5 h. A solution of 2,4-dichloro-pyridine (2.9 g, 20 mmol) in N,N-dimethyl-acetamide was added, and the reaction was heated to 100° C. under nitrogen for 10 h. After cooling to RT, the reaction was poured into water (100 mL) and the aqueous solution was extracted with ethyl acetate (3×70 mL). The combined organics were washed with brine, dried (Na2SO4), concentrated in vacuo and purified by silica gel chromatography to give 4-(2-chloropyridin-4-yloxy)-3,5-difluoroaniline (3.0 g, 59% yield). 1H NMR (300 MHz, DMSO-d6): δ 8.31 (d, J=5.7 Hz, 1H), 7.10 (d, J=2.1 Hz, 1H), 7.01 (dd, J=5.7 Hz, 2.1 Hz, 1H), 6.38 (d, J=10.8 Hz, 2H), 5.86 (s, 2H).

1. temperaturethe reaction was heated to 100° C. under nitrogen for 10 h
2. temperatureAfter cooling to RT
3. extractionthe aqueous solution was extracted with ethyl acetate (3×70 mL)
4. washThe combined organics were washed with brine
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated in vacuo
7. custompurified by silica gel chromatography