反应详情

3-Hydroxypyridin-2(1H)-one (15 g, 135 mmol) and imidazole (23 g, 338 mmol) were suspended in dimethylformamide (200 mL) under inert atmosphere. A solution of tert-butyldimethylsilyl chloride (20.5 g, 136 mmol) in dimethylformamide (200 mL) is added dropwise at room temperature over 30 minutes. The reaction was then allowed to stir overnight. The resulting solution was then poured into water (300 mL) and the mixture extracted with tert-butyl methyl ether (3×500 mL). The combined organic layer was washed with water (300 mL), brine (300 mL) then dried over Na2SO4. The solvent is removed under reduced pressure and the crude product crystallized from heptanes to afford 16.3 g (53% yield) of the desired product. 1H NMR (250 MHz, CDCl3) δ ppm 12.98 (1H, m); 6.91 (1H, dd, J=1. Hz, J=6.8 Hz); 6.81 (1H, dd, J=1.8 Hz, J=7.2 Hz); 6.02-6.007 (1H, m); 0.90 (9H, s), and 0.17 (6H, s).

1. extractionthe mixture extracted with tert-butyl methyl ether (3×500 mL)
2. washThe combined organic layer was washed with water (300 mL), brine (300 mL)
3. dry with materialthen dried over Na2SO4
4. customThe solvent is removed under reduced pressure
5. customthe crude product crystallized from heptanes