反应详情

Bis(trichloromethyl) carbonate (3.73 g, 12.57 mmol) was added to a solution of 2-amino-4-fluorobenzoic acid (1.3 g, 8.38 mmol) in sodium hydroxide (2N in water) (8.80 mL, 17.60 mmol) and water (9 mL) at room temperature. The resulting suspension was stirred for 15 minutes then toluene (9.00 mL) was added. The mixture was stirred at room temperature for 18 hours. The resulting precipitate was collected by filtration, washed with water, followed by 20% acetronitrile in Et2O (10 mL) and dried under vacuum at 40° C. to afford 7-fluoro-1H-3,1-benzoxazine-2,4-dione (0.852 g, 56.1%) as a off-white solid.

1. stirringThe mixture was stirred at room temperature for 18 hours
2. filtrationThe resulting precipitate was collected by filtration
3. washwashed with water
4. customdried under vacuum at 40° C.