反应详情

To a solution of 8-bromo-5,6-difluoro-2,3-dihydrochromen-4-one (7.2 mmol) in 40 mL of ethanol was added hydroxylamine hydrochloride (0.55 g, 7.9 mmol) and sodium acetate (0.65 g, 7.9 mmol). This mixture heated at reflux for 20 hrs. The mixture was cooled, diluted with EtOAc, washed with water and brine, and then dried over Na2SO4. Concentration of the solvent provided the title compound as a white solid (1.9 g). 1H NMR (300 MHz, 10% CD3OD in CDCl3): δ 7.3 (t, 1H), 4.2 (t, 2H), 2.9 (t, 2H).

1. temperatureThis mixture heated
2. temperatureat reflux for 20 hrs
3. temperatureThe mixture was cooled
4. washwashed with water and brine
5. dry with materialdried over Na2SO4