反应详情

2-(1H-Benzotriazole-1-yl)-1,1,3,3,-tetramethyluronium hexafluorophosphate (2.060 g, 5.43 mmol), O,N-dimethylhydroxylamine hydrochloride (0.583 g, 5.97 mmol) and a catalytic amount of dimethylformamide are added to a suspension of (E)-3-(3,4-difluorophenyl)prop-2-enoic acid (1 g, 5.43 mmol) in tetrahydrofuran (20 mL). The resulting solution is stirred at room temperature for 3 h. The solution is diluted with ethyl acetate (20 mL) and is washed with sequentially with aqueous saturated ammonium chloride (10 mL), water (10 mL), aqueous saturated sodium hydrogen carbonate (10 mL) and with brine (10 mL). The organic layer is then dried over sodium sulphate, filtered and concentrated under reduced pressure. The crude product isolated is purified by flash column chromatography on silica gel (heptane/ethyl acetate 0 to 60% as eluent) to afford the desired product as a white solid (478 mg, 2.104 mmol, 39% yield).

1. washis washed with sequentially with aqueous saturated ammonium chloride (10 mL), water (10 mL), aqueous saturated sodium hydrogen carbonate (10 mL)
2. dry with materialThe organic layer is then dried over sodium sulphate
3. filtrationfiltered
4. concentrationconcentrated under reduced pressure
5. customThe crude product isolated
6. customis purified by flash column chromatography on silica gel (heptane/ethyl acetate 0 to 60% as eluent)