反应详情

温度

50 °C

Thus, 18.5 g of selenium dioxide was dissolved in 100 mL of dioxane by warming to 50° C. and stirring until all was in solution. To this solution was added. 23 g of 4′-fluoroacetophenone and the reaction was refluxed for 4 h. The hot solution was decanted from the solid selenium and the dioxane and water were removed by distillation through a short column at atmospheric pressure. Distillation of the residue at reduced pressure afforded 20 g of 4-fluorophenylglyoxal as a thick yellow oil which was contaminated by some starting 4′-fluoroacetophenone. This can be used directly or, more preferably, it can be converted to pure hydrate (see the last paragraph of the reference and note 5). A portion was boiled in water for 0.5 h and the aqueous layer was decanted from an oily residue and then allowed to cool. The hydrate is obtained as a white solid after filtration and air drying.

1. additionTo this solution was added
2. customThe hot solution was decanted from the solid selenium
3. customthe dioxane and water were removed by distillation through a short column at atmospheric pressure
4. distillationDistillation of the residue at reduced pressure