PROCESS FOR PREPARING GABAPENTIN

摘要

The present invention provides compositions and methods of preparing gabapentin that includes (a) subjecting cyclohexanediacetic acid monoamide t o a Hofmann rearrangement to yield a solution comprising an isocyanate intermediate; (b) hydrolyzing the isocyanate intermediate in the presence of an alkali base to form a gabapentin alkali salt; (c) converting the gabapent in alkali salt to a gabapentin-amine salt in a water-miscible polar solvent; (d ) adding a basic or weakly basic ion exchange resin to a solution comprising t he gabapentin-amine salt; (e) removing the ion exchange resin from the solution ; and (f) concentrating the solution to yield gabapentin.