During the process development of Pregabalin 1, a known anticonvulsantdrug, six potential impurities were identified in the final crude material ranging from 0.01 to 0.15% by LCMS. All six impurities were subsequently synthesized and characterized by IR, MS and NMR spectral data. Four of the six related substances are known as 4-isobutylpyrrolidin-2-one 6, 3- isobutylglutaric acid 2, (R)-(-)-3-ca