反应详情

温度

90 °C

A mixture of the compound of part (ii) (40 kg) and water (10 kg) was heated to 90° C. and 4N aqueous sodium hydroxide solution (127 L) added. Heating was continued at 80° C. for 30 minutes and then the mixture was cooled to 25° C. The mixture was washed with toluene (124 L), the aqueous layer separated and dichloromethane (162 L) added thereto. To this mixture was added concentrated hydrochloric acid until pH1 was achieved. The organic layer was separated and the aqueous layer extracted with dichloromethane (162 L). The combined organic layers were treated with activated carbon (Norit-trade mark) (8.8 kg). The solution was filtered and the filtrate treated with concentrated aqueous ammonia solution until pH9 was achieved. The product precipitated as a solid and was collected by filtration (34 kg), m.p. 125–131° C.

1. temperatureHeating
2. temperaturethe mixture was cooled to 25° C
3. washThe mixture was washed with toluene (124 L)
4. customthe aqueous layer separated
5. additiondichloromethane (162 L) added
6. additionTo this mixture was added concentrated hydrochloric acid until pH1
7. customThe organic layer was separated
8. extractionthe aqueous layer extracted with dichloromethane (162 L)
9. additionThe combined organic layers were treated with activated carbon (Norit-trade mark) (8.8 kg)
10. filtrationThe solution was filtered
11. additionthe filtrate treated with concentrated aqueous ammonia solution until pH9
12. customThe product precipitated as a solid
13. filtrationwas collected by filtration (34 kg), m.p. 125–131° C.