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 with stirring. The slurry-like reaction mixture is extracted hot with 3-4 times 1 liter of methanol, the combined methanol extracts are evaporated and the residue is recrystallised from methanol. 55 g of 2,3-dihydro-2,2-dimethyl-6-(2-bromoethoxy)-4H-1,3-benzoxazin-4-one with a melting point of 190°-195° are obtained.

1. temperatureis refluxed for 4 hours
2. customThe slurry-like reaction mixture
3. extractionis extracted hot with 3-4 times 1 liter of methanol
4. customthe combined methanol extracts are evaporated
5. customthe residue is recrystallised from methanol