反应详情

温度

9 °C

50 g of donepezil was dissolved by stirring in 315 g of ethanol under heating, followed by adding 15.1 g of concentrated hydrochloric acid thereto at the internal temperature of 30° C. Then, it was cooled and continued stirring while keeping the internal temperature at 30° C. Crystals started precipitating about 30 minutes after the concentrated hydrochloric acid was poured into the mixture. After the precipitation started, the mixture was stirred at the internal temperature of 15° C. for 18 hours and then cooled to the internal temperature of 9° C. The crystals were collected by filtration and dried about 4 hours after the cooling was started, to give 52.32 g of polymorphic crystal (III) of donepezil hydrochloride (yield: 95.5%).

1. temperatureunder heating
2. customat the internal temperature of 30° C
3. temperatureThen, it was cooled
4. customat 30° C
5. customCrystals started precipitating about 30 minutes after the concentrated hydrochloric acid
6. additionwas poured into the mixture
7. customAfter the precipitation
8. stirringthe mixture was stirred at the internal temperature of 15° C. for 18 hours
9. filtrationThe crystals were collected by filtration
10. customdried about 4 hours after the cooling