Hydrochloric Acid → Gabapentin hydrochloride

Participants

Reaction Conditions

Reaction Steps

22.3 1 of water and 22.3 1 of concentrated hydrochloric acid are mixed in a T100 reactor and 6.41 kg gabapentin lactam added thereto, while stirring. The clear brown solution formed is subsequently boiled under reflux for six hours at 108° C. and the reaction mixture is left to stand 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 dichloromethane. The pale yellow aqueous phase is evaporated to dryness in a vacuum evaporator (QVF 100 L), the temperature finally reaching to 80° C. at 133 Pa. The almost dry crystal mass is stirred in 12.8 l acetone and filtered off with suction. It is then washed with 2 l acetone and dried for four hours at 60° C. The yield is about 60% of theory.

Provenance & Evidence