反应详情

The starting material is prepared as follows: 2,5-Dihydroxybenzaldehyde (25.0 g, 0.18 mol) is dissolved in 375 ml of 1,4-dioxane. To this is sequentially added potassium carbonate (50.0 g, 0.36 mol) and acrolein (15.22 g, 0.27 mol). The mixture is heated at reflux overnight, cooled, and partitioned between water and ether. The aqueous layer is removed and extracted twice with ether. The combined organic layers are dried (MgSO4) and evaporated. Trituration of the residue with dichloromethane, followed by filtration and drying, yields 6-hydroxy-2H-1-benzopyran-3-carboxaldehyde, m.p. 163°-165° C., as a yellow crystalline solid.

1. customThe starting material is prepared
2. temperatureThe mixture is heated
3. temperatureat reflux overnight
4. temperaturecooled
5. custompartitioned between water and ether
6. customThe aqueous layer is removed
7. extractionextracted twice with ether
8. dry with materialThe combined organic layers are dried (MgSO4)
9. customevaporated
10. filtrationTrituration of the residue with dichloromethane, followed by filtration
11. customdrying