反应详情

1.1 3.8 g of sodium are dissolved in portions in 300 ml of ethanol with stirring. A solution of 5.0 g of 2,5-dihydroxyacetophenone and 17.8 ml of diethyl oxalate in 25 ml of ethanol is subsequently added dropwise. The reaction mixture is then heated at 80° for 3 hours and cooled to room temperature, and 10 ml of 32% HCl are added dropwise. The mixture is heated at 90° for 30 minutes and cooled, and the solvent is removed. Conventional work-up gives 5.6 g of 6-hydroxy-2-ethoxycarbonylchromen-4-one (“AA”).

1. temperatureThe reaction mixture is then heated at 80° for 3 hours
2. temperatureThe mixture is heated at 90° for 30 minutes
3. temperaturecooled
4. customthe solvent is removed