Hydrochloric Acid → Gabapentin hydrochloride

Temperature

108 °C

22.3 L of water and 22.3 L of concentrated hydrochloric acid are mixed in a T100 reactor and 6.41 kg gabapentin lactam added while stirring. The clear brown solution formed is subsequently boiled under reflux at 108° C. for 6 hours. The reaction mixture is then left until it has cooled to 28° C. The white precipitate obtained is again dissolved by the addition of a further 40 L of water. For the removal of still undissolved lactam, the reaction mixture is extracted three times with, in each case, 30 L of dichloromethane. The pale yellow aqueous phase is evaporated to dryness in a vacuum evaporator (QVF 100L). At 133 Pa, the temperature finally reached 80° C. The almost dry crystal mass is stirred up with 12.8 L of acetone and sucked off. It is then washed with 2 L of acetone and dried for 4 hours at 60° C. The yield is about 60% of theory.

1. additionadded
2. customThe clear brown solution formed
3. waitThe reaction mixture is then left until it
4. temperaturehas cooled to 28° C
5. customThe white precipitate obtained
6. customFor the removal of still undissolved lactam
7. extractionthe reaction mixture is extracted three times with, in each case, 30 L of dichloromethane
8. customThe pale yellow aqueous phase is evaporated to dryness in a vacuum evaporator (QVF 100L)
9. customthe temperature finally reached 80° C
10. stirringThe almost dry crystal mass is stirred up with 12.8 L of acetone
11. washIt is then washed with 2 L of acetone
12. customdried for 4 hours at 60° C

ORD record

ord-8dec84db86f0458aae138ae61dfcb3c6

Source dataset

uspto-grants-2000_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06054482