反应详情

To 2-amino-5-chloro-3-methoxybenzoic acid (0.72 g, 3.57 mmol) in anhydrous tetrahydrofuran (15 mL) was added triphosgene (0.53 g, 1.8 mmol). The mixture was heated to refluxed under a nitrogen atmosphere for 2.5 hours. The resulting solution was cooled to ambient temperature, diethyl ether (10 mL) was added, which caused a solid to precipitate. The solid was collected by filtration and washed with more diethyl ether to yield 6-chloro-8-methoxy-1H-benzo[d][1,3]oxazine-2,4-dione. MS (m/z): 226.3, 228.3 (M+H)+.

1. temperatureThe mixture was heated
2. temperatureto refluxed under a nitrogen atmosphere for 2.5 hours
3. customto precipitate
4. filtrationThe solid was collected by filtration
5. washwashed with more diethyl ether