反应详情

49.5 g (175 mmol) 7-acetyl-4-benzyloxy-3H-benzoxazol-2-one and 19.6 g (177 mmol) selenium dioxide are refluxed for 8 hours in 200 mL dioxane and 8 mL water in the presence of activated charcoal. The insoluble constituents are suction filtered, the solvent is distilled off and the residue is combined with 150 mL ethanol. The mixture is refluxed for 30 minutes and then filtered through activated charcoal. After the addition of a crystallisation aid the product is precipitated out of the cooled solution. It is suction filtered and washed with ethanol and diethyl ether.

1. distillationthe solvent is distilled off
2. temperatureThe mixture is refluxed for 30 minutes
3. filtrationfiltered through activated charcoal
4. additionAfter the addition of a crystallisation aid the product
5. customis precipitated out of the cooled solution
6. filtrationfiltered
7. washwashed with ethanol and diethyl ether