Hydrochloric Acid → Gabapentin hydrochloride

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence