反应详情

温度

100 °C

A mixture of 2-amino-5-ethylbenzoic acid (20.28 g) and ethyl chlorocarbonate (53.5 g) was stirred for 50 minutes at 100° C. and then cooled to 90° C. To the mixture was added dropwise acetyl chloride (13.81 g) in the course of 15 minutes and the reaction mixture was stirred for 2 hours at 100° C. After the resultant mixture was cooled to ambient temperature, to the mixture was added hexane and allowed to stand at ambient temperature to give crystals, which were separated by filtration, washed with hexane and dried under reduced pressure to give crystalline 6-ethyl-2H-3,1-benzoxazine-2,4(1H)-dione (19.55 g).

1. temperaturecooled to 90° C
2. stirringthe reaction mixture was stirred for 2 hours at 100° C
3. customto stand at ambient temperature
4. customto give crystals, which
5. customwere separated by filtration
6. washwashed with hexane
7. customdried under reduced pressure