反应详情

As shown in step 3(a)-v of Scheme 3(a), 5-bromo-3-(difluoromethoxy)pyridin-2-ol (300 mg; 1.25 mmol) was dissolved in 5 mL of chloroform. Silver carbonate (690 mg; 2.5 mmol) and methyl iodide (780 μL; 1.77 g; 12.5 mmol) were added and the mixture stirred at RT overnight. The reaction mixture was filtered through diatomaceous earth, which was washed with additional CHCl3. The filtrates were concentrated under reduced pressure to yield an oil which was purified by silica gel chromatography to yield 5-bromo-3-(difluoromethoxy)-2-methoxypyridine as a white solid (Compound 2010, 250 mg, 78% yield): ESMS (M+H) 254/256; 1H NMR (CDCl3) δ 8.08 (d, 1H, J=2.1 Hz), 7.56 (d, 1H, J=2.1 Hz), 6.60 (t, 1H, J=75 Hz), 3.98 (s, 3H).

1. filtrationThe reaction mixture was filtered through diatomaceous earth, which
2. washwas washed with additional CHCl3
3. concentrationThe filtrates were concentrated under reduced pressure
4. customto yield an oil which
5. customwas purified by silica gel chromatography