反应详情

7-bromo-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one (1.5 g, 6.55 mmol) and NBS (5.83, 32.7 mmol) were heated to 80° C. in DMF (30 ml) for 2 hours. The resulting reaction mixture was diluted with ethyl acetate (30 ml) and water (30 ml). The aqueous phase was extracted with fresh ethyl acetate (50 ml×3) and the combined organic layers were washed with brine (50 ml), dried on anhydrous Na2SO4, filtered and concentrated to dryness under reduced pressure to give the title compound (1.6 g, 79%). It was used for the next step without further purification. LCMS (Method D): RT=0.91 min, M+1=309.

1. customThe resulting reaction mixture
2. extractionThe aqueous phase was extracted with fresh ethyl acetate (50 ml×3)
3. washthe combined organic layers were washed with brine (50 ml)
4. dry with materialdried on anhydrous Na2SO4
5. filtrationfiltered
6. concentrationconcentrated to dryness under reduced pressure