Hydrogen Bromide → Pregabalin

Participants

Reaction Steps

A flask was loaded with 47% HBr (30 ml), water (15 ml), and compound 26 (15 g), and then was heated to reflux for 3 hours. The solution was cooled to room temperature and water (30 ml) was added. An aqueous 47% sodium hydroxide solution was added to obtain pH of 3. The solution was then extracted twice with iso-butanol (37.5 ml). The organic layers were combined and Bu3N (9.5 g) was added. The mixture was cooled to 2° C. for 1 hour, then (S) -Pregabalin was filtered, and washed with of iso-butanol (10 ml). After drying at 55° C. under vacuum, (S)-Pregabalin was obtained as white crystals in a 51% yield.

Provenance & Evidence