反应详情

A solution of 5-bromo-3-chloromethylpyridinium hydrochloride (716 mg, 4.189 mmol) in anhydrous DMF (15 mL) under nitrogen at 0° C. was treated with triethylamine (0.65 mL, 4.61 mmol), tetrabutylammonium bromide (273 mg, 0.838 mmol), and potassium di-tert-butyl imidodicarbonate (1.284 g, 5.027 mmol). The reaction was heated to 50° C.-55° C. for 3.5 hours, then cooled to room temperature, diluted with ethyl acetate (150 mL), and washed with water (2×50 mL) and saturated aqueous sodium chloride. The combined extracts were dried over anhydrous Na2SO4, filtered, and concentrated by rotary evaporation. The residue was purified by flash column chromatography on silica gel with 6% ethyl acetate/dichloromethane to give the title compound as a colorless oil (0.980 g, 60%). MS (ESI+) m/z 387/389 (M+H)+; 1H NMR (300 MHz, CDCl3) δ 1.49 (s, 18H), 4.75 (s, 2H), 7.83 (t, J=2.02 Hz, 1H), 8.50 (d, J=1.84 Hz, 1H), 8.58 (d, J=2.21 Hz, 1H).

1. temperatureThe reaction was heated to 50° C.-55° C. for 3.5 hours
2. washwashed with water (2×50 mL) and saturated aqueous sodium chloride
3. dry with materialThe combined extracts were dried over anhydrous Na2SO4
4. filtrationfiltered
5. concentrationconcentrated by rotary evaporation
6. customThe residue was purified by flash column chromatography on silica gel with 6% ethyl acetate/dichloromethane