Hydrochloric Acid → Tiagabine

Participants

Reaction Conditions

Reaction Steps

To a 1 L flask, 50 g of tiagabine ethyl ester, 575 ml of water and 25 g of conc. hydrochloric acid were charged. The mixture was heated to reflux for 1 hour and then ethanol/water, a total of 200 ml, was distilled off over a period of 4 hours. The reaction solution was cooled to 88° C. and then an additional 23.5 g of conc. hydrochloric acid was added. The solution was gradually cooled to room temperature (22° C.) while the reaction was stirred for 18 hours. The resulting precipitate was collected by filtration and was washed with 20 ml of water. The product was dried under vacuum at room temperature to give 42.0 g of Tiagabine, hydrochloride.

Provenance & Evidence