反应详情

To a solution of ethyl cyanoacetate (7.24 g) and diisopropylethylamine (19.9 g) in tetrahydrofuran (30 mL) was added dropwise a solution of 2-bromo-1-(2,6-difluorophenyl)ethanone (15.16 g) in tetrahydrofuran (15 mL) at 10-15° C. The mixture was stirred at room temperature for 12 hr. The reaction mixture was filtered, and the obtained filtrate was concentrated under reduced pressure. The residue was dissolved in ethyl acetate, washed successively with water, 1 mol/L hydrochloric acid and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate=4:1→3:2) to give the title compound as a pale-green oil (yield 13.8 g, 81%).

1. filtrationThe reaction mixture was filtered
2. concentrationthe obtained filtrate was concentrated under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate
4. washwashed successively with water, 1 mol/L hydrochloric acid and saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate=4:1→3:2)