反应详情

5.76 g (40.1 mmol) of 4-chloro-2-methoxypyridine was dissolved in 20 ml of dimethylformamide, and a dimethylformamide (20 ml) solution of 8.01 g of N-bromosuccinimide (98%, 44.1 mmol) was dropwise added over a period of 30 minutes. After stirring at room temperature for 2 days, an unreacted material was confirmed, and thus 2.85 g of N-bromosuccinimide (98%, 16 mmol) was further added, followed by stirring at room temperature further for 3 days. The reaction mixture was poured into 250 ml of water, followed by extraction with ethyl ether (100 ml each) three times. The organic layer was washed with water (100 ml), a sodium thiosulfate aqueous solution (100 ml) and then a saturated sodium chloride solution (100 ml), dried over magnesium sulfate and subjected to filtration, and the solvent was distilled off under reduced pressure. The obtained crude product was purified by silica gel chromatography to obtain 7.10 g (yield: 80%) of 5-bromo-4-chloro-2-methoxypyridine.

1. stirringby stirring at room temperature further for 3 days
2. extractionfollowed by extraction with ethyl ether (100 ml each) three times
3. washThe organic layer was washed with water (100 ml)
4. dry with materiala sodium thiosulfate aqueous solution (100 ml) and then a saturated sodium chloride solution (100 ml), dried over magnesium sulfate
5. filtrationsubjected to filtration
6. distillationthe solvent was distilled off under reduced pressure
7. customThe obtained crude product
8. customwas purified by silica gel chromatography