反应详情

5-[(7-Bromo-2,3-dihydro-benzo[1,4]dioxin-6-ylamino)-methylene]-2,2-dimethyl-[1,3]dioxane-4,6-dione (22.9 g, 59.6 mmol) was added portionwise to refluxing Dowtherm A® (45 mL) over 3 minutes. After a further 3 minutes at reflux the mixture was cooled to room temperature. Ethyl acetate/hexane (10 mL/20 mL) was added and a black solid isolated by filtration. This residue was dissolved in hot methanol (400 mL) and filtered through Keiselguhr. Water (800 mL) was added and the mixture stored at 5° C. overnight. Filtration and drying afforded a pale yellow solid (10.3 g, 61%).

1. temperatureAfter a further 3 minutes at reflux the mixture
2. customa black solid isolated by filtration
3. filtrationfiltered through Keiselguhr
4. additionWater (800 mL) was added
5. filtrationFiltration
6. customdrying