反应详情

5-Aminopyridine-2-carbonitrile (2.38 g, 20 mmol) was dissolved in 6 mL of glacial acetic acid. A solution of bromine (1 mL, 20 mmol) in 2.5 mL of glacial acetic acid was added dropwise over a period of 30 minutes while the room temperature was maintained with a water bath. The resulting slurry was stirred for 1 hour at room temperature, treated with 50 mL of aqueous 20% sodium hydroxide solution and extracted with three 160 mL portions of dichloromethane. The combined organic layers were dried over sodium sulfate (Na2SO4), filtered, and concentrated in vacuo. The residue was purified by crystallization from ethyl acetate-hexanes to give 5-amino-6-bromopyridine-2-carbonitrile (1.42 g, 35% yield).

1. temperaturewas maintained with a water bath
2. extractionextracted with three 160 mL portions of dichloromethane
3. dry with materialThe combined organic layers were dried over sodium sulfate (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by crystallization from ethyl acetate-hexanes