反应详情

2-Cyclopropyl-6-[1-(ethoxy)ethenyl]-7-methoxy-5-methyl-1,3-benzoxazole-4-carbonitrile (I-84) (2.58 g, 8.46 mmol) was dissolved in tetrahydrofuran (130 ml), water (7.7 ml) and N-bromosuccinimide (1.61 g, 8.89 mmol) were added all at a time, followed by stirring at room temperature for 1.5 hours. After the reaction, the solvent was evaporated away under reduced pressure, followed by dilution with ethyl acetate and by washing with water and saturated brine. The obtained organic layer was dried over anhydrous sodium sulfate, the solvent was evaporated away under reduced pressure. The resulting residue was subjected to silica gel column chromatography (covering) and eluted with a mixed solvent of n-hexane/ethyl acetate (2:1, v/v) to obtain the entitled compound (2.40 g, 81%) as a yellow white solid.

1. customAfter the reaction
2. customthe solvent was evaporated away under reduced pressure
3. washby washing with water and saturated brine
4. dry with materialThe obtained organic layer was dried over anhydrous sodium sulfate
5. customthe solvent was evaporated away under reduced pressure
6. washeluted with a mixed solvent of n-hexane/ethyl acetate (2:1