反应详情

Into a 500-mL round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed a solution of (4-bromopyridin-2-yl)methanamine (compound 39.1, 4.5 g, 24.1 mmol) in dichloromethane (160 mL). Triethylamine (6.72 mL, 48.2 mmol) and acetic anhydride (2.29 mL, 24.2 mmol) were carefully added and the resulting solution was stirred at room temperature for 12 h. The volatiles were removed under reduced pressure and the residue was slowly quenched with water (200 mL). The pH of the solution was slowly adjusted to 9-12 with aqueous sodium carbonate (3 M) and the aqueous phase was extracted with ethyl acetate (3×60 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography with dichloromethane/methanol (100:1-10:1) as the eluent to yield 4.0 g (73%) of the title compound as yellow oil.

1. customInto a 500-mL round-bottom flask, purged
2. temperaturemaintained with an inert atmosphere of nitrogen
3. customThe volatiles were removed under reduced pressure
4. customthe residue was slowly quenched with water (200 mL)
5. extractionthe aqueous phase was extracted with ethyl acetate (3×60 mL)
6. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by silica gel column chromatography with dichloromethane/methanol (100:1-10:1) as the eluent