反应详情

温度

5 °C

To a solution of 7-chloro-2H-3,1-benzoxazine-2,4(1H)-dione (330 g) in N,N-dimethylformamide (3.3 l) was added sodium hydride (60% in mineral oil, 86.8 g) below 20° C. and the mixture was stirred at 5° C. for 30 minutes. To this solution was added ethyl bromoacetate (222 ml) at 10° C. over a 30-minute period and the resulting mixture was stirred at room temperature for 1.5 hours. To this reaction mixture was added 28% aqueous ammonia (696 ml) below 10° C. and the resulting mixture was stirred at 5° C. for 20 minutes. The mixture was poured into 1N hydrochloric acid (16.5 l). The precipitates were collected by filtration, and washed in turn with water (3 times) and diethyl ether to give ethyl N-(2-carbamoyl-5-chlorophenyl)aminoacetate (360 g).

1. stirringthe resulting mixture was stirred at room temperature for 1.5 hours
2. stirringthe resulting mixture was stirred at 5° C. for 20 minutes
3. filtrationThe precipitates were collected by filtration
4. washwashed in turn with water (3 times) and diethyl ether