反应详情

A mixture of 48.2 g of 2,3-dihydro-2,2-dimethyl-6-hydroxy-4H-1,3-benzoxazin-4-one, 70 g of potassium carbonate and 250 ml of 1,2-dibromoethane is refluxed for 4 hours whilst stirring. The semi-liquid reaction mixture is extracted 3 to 4 times whilst hot with 1 liter of methanol each time; the combined methanol extracts are concentrated by evaporation and the residue is recrystallised from methanol. 6-(2-Bromoethoxy)-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one having a melting point of 190°-195° is obtained.

1. temperatureis refluxed for 4 hours
2. customThe semi-liquid reaction mixture
3. extractionis extracted 3 to 4 times whilst hot with 1 liter of methanol each time
4. concentrationthe combined methanol extracts are concentrated by evaporation
5. customthe residue is recrystallised from methanol