反应详情

温度

50 °C

27.9 g (0.15 mol) of 3-(2,4-difluorophenyl)propanoic acid are mixed in a sulfation flask with 50 ml (0.69 mol) of thionyl chloride and 0.5 ml of dimethylformamide, and the mixture is stirred at room temperature for one hour, at 50° C. for one hour and under reflux for half an hour. The excess thionyl chloride is then removed by distillation in vacuo. The orange-brown oily residue is dissolved in toluene and then cooled to -15° C. At this temperature, 7.0 g (0.41 mol) of ammonia gas are passed in over about one hour. The temperature is then allowed to rise to room temperature. The partially crystalline reaction mixture is then poured into 500 ml of ice-water. The residue is filtered, washed with a little toluene and dried in vacuo. 21.7 (78% of theory) of white crystals of melting point 107°-108° C. are obtained. After recrystallization from water, the product melts at 109°-110° C.

1. temperatureunder reflux for half an hour
2. customThe excess thionyl chloride is then removed by distillation in vacuo
3. dissolutionThe orange-brown oily residue is dissolved in toluene
4. temperaturecooled to -15° C
5. customare passed in over about one hour
6. customto rise to room temperature
7. filtrationThe residue is filtered
8. washwashed with a little toluene
9. customdried in vacuo
10. custom21.7 (78% of theory) of white crystals of melting point 107°-108° C. are obtained
11. customAfter recrystallization from water