反应详情

Trifluoroacetic anhydride (0.35 mL, 2.5 mmol) was added dropwise to a solution of 3-bromo-5-fluoro-2,4-dimethylpyridine 1-oxide (220 mg; 1.0 mmol) in DCM (3 mL). The reaction mixture was stirred at room temperature overnight and then diluted with ethyl acetate (50 mL) and washed with saturated aqueous sodium bicarbonate solution (20 mL). The organic layer was separated, dried over sodium sulfate, filtered and concentrated in vacuo to provide a residue that was purified by flash chromatography (4 g, Silica, 0-100% ethyl acetate in heptane). Desired fractions were combined and evaporated in vacuo to afford the title compound as a pale yellow oil (150 mg, 68%), which was used in the next step without further purification.

1. washwashed with saturated aqueous sodium bicarbonate solution (20 mL)
2. customThe organic layer was separated
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customto provide a residue that
7. customwas purified by flash chromatography (4 g, Silica, 0-100% ethyl acetate in heptane)
8. customevaporated in vacuo