反应详情

To a solution of 2-aminopyrazine (5.25 g, 55.2 mmol) in ethanol (120 mL) was added 1-bromo-3,3,3-trifluoroacetone (5.73 mL, 55.2 mmol). The reaction was stirred at reflux for 20 h. After evaporation of solvent, the residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution. The aqueous layer was extracted three times with ethyl acetate. The combined organic phase was washed with saturated brine solution, dried over magnesium sulfate and concentrated. The residue was purified by flash chromatography (silica gel, 1:1 ethyl acetate:hexane, then 100% ethyl acetate) to give the title compound as a solid. 1H NMR (500 MHz, CDCl3): δ 8.02 (m, 2H), 8.13 (m, 1H), 9.22 (s, 1H). ESI-MS 188 (M+1).

1. temperatureat reflux for 20 h
2. customAfter evaporation of solvent
3. customthe residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution
4. extractionThe aqueous layer was extracted three times with ethyl acetate
5. washThe combined organic phase was washed with saturated brine solution
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated
8. customThe residue was purified by flash chromatography (silica gel, 1:1 ethyl acetate