反应详情

To a solution of 3-(benzyloxy)-5-bromopyridin-2-ol ((5.8 g, 20.7 mmol) in DMF (75 mL) was added Cs2CO3 (8.8 g, 26.9 mmol). A solution of MeI (1.62 mL, 25.9 mmol) in DMF (10 mL) was added dropwise to this mixture. After stirring at room temperature for 3 h, the reaction mixture was concentrated. The residue was taken up in H2O and the aqueous solution was extracted with CH2Cl2 (3×). Combined organic solutions washed with brine (1×), dried over Na2SO4 and concentrated. Purification by flash chromatography (250 g silica gel, 50% EtOAc in hexanes) afforded 4.02 g (66%) of 3-(benzyloxy)-5-bromo-1-methylpyridin-2(1H)-one as a white solid. 1H NMR (500 MHz, CDCl3): δ 7.43-7.32 (m, 5H), 7.05 (s, 1H), 6.91 (s, 1H), 5.11 (s, 2H).

1. concentrationthe reaction mixture was concentrated
2. extractionthe aqueous solution was extracted with CH2Cl2 (3×)
3. washCombined organic solutions washed with brine (1×)
4. dry with materialdried over Na2SO4
5. concentrationconcentrated
6. customPurification by flash chromatography (250 g silica gel, 50% EtOAc in hexanes)