反应详情

温度

50 °C

To a solution of 5-methyl-4H-3,1-benzoxazin-2,4-dione (Preparation VIIA) (19.7 g, 111 mmol) in methanesulfonic acid (150 mL) was added N-(hydroxymethyl)phthalimide (20.3 g, 111 mmol). The reaction mixture was heated to 50° C. and stirred for 3 hours. After cooling to room temperature, the reaction mixture was diluted with 2000 mL of Et2O. After stirring for an additional 1 hour, the precipitate was filtered, washed with Et2O and dried affording 30.7 g of crude phthalamide. 1H NMR showed a 3:2 mixture of the 6- and 8-substituted regioisomers respectively. The crude material was used directly in the next reaction where the two regeoisomers were separated.

1. temperatureAfter cooling to room temperature
2. stirringAfter stirring for an additional 1 hour
3. filtrationthe precipitate was filtered
4. washwashed with Et2O
5. customdried