Pregabalin is prepared at three different sites through a two-step chemical synthesis. The first step consists of the synthesis of pregabalin racemate from commercially available starting materials. The undesired R enantiomer is subsequently removed by a classical resolution method. Pregabalin crude is terminally purified by recrystallisation from isopropyl alcohol and water to give pregabalin.
Some identified non-clinical and clinical batches have been produced by a different synthetic route, but with essentially the same specification (no major differences in impurity profile).
Satisfactory specifications and associated methods have been provided for the starting materials, key intermediate (pregabalin racemate), reagents and solvents.