反应详情

To a stirred suspension of 2-chloro-6-methoxy-3-nitropyridine (2.44 g, 12.9 mmol) in 10% v/v aqueous dioxane (25 mL) was added tetrakis(triphenyl phosphine) palladium (1.50 g, 1.3 mmol) and the mixture stirred for 15 min prior to the addition of trimethylboroxine (1.81 mL, 12.9 mmol) and potassium carbonate (5.36 g, 38.8 mmol). The reaction mixture was heated under reflux for 6 h then allowed to cool to rt over 16 h. Ethyl acetate (100 mL) was added and the mixture stirred vigorously for 1 h. The mixture was filtered through celite, washing through with ethyl acetate. The aqueous phase was separated and extracted with ethyl acetate (3×30 mL) and the combined organics were washed with brine (50 mL), dried (MgSO4), filtered and adsorbed onto silica gel. Purification via flash column chromatography (SiO2, ethyl acetate/isohexane, 1:20) gave the title compound as a pale yellow solid. δH (CDCl3): 2.81 (3H, s), 4.01 (3H, s), 6.65 (1H, d), 8.26 (1H, d).

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 6 h
3. stirringthe mixture stirred vigorously for 1 h
4. filtrationThe mixture was filtered through celite
5. washwashing through with ethyl acetate
6. customThe aqueous phase was separated
7. extractionextracted with ethyl acetate (3×30 mL)
8. washthe combined organics were washed with brine (50 mL)
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. customPurification via flash column chromatography (SiO2, ethyl acetate/isohexane, 1:20)