Patent ID: 7442834

Claim:
A process for the preparation of highly pure, stable compound of formula comprising: (a) converting cyclohexane 1,1-diacetic acid monoamide to 3,3-pentamethylenebutyrolactam by reacting cyclohexane 1,1-diacetic acid monoamide with hypochlorite; (b) hydrolyzing 3,3-pentamethylenebutyrolactam to gabapentin salt under acidic condition at 50-120° C., cooling the reaction mixture to precipitate gabapentin salt, and collecting the gabapentin salt from the mother liquor by filtration; (c) adding gabapentin salt to purified water and adjusting the pH to 8-8.5 with a base, cooling the mixture to 10-20° C. to precipitate gabapentin hydrate, and collecting the gabapentin hydrate from the mother liquor by filtration; (d) dehydrating gabapentin hydrate in alcohol or water-alcohol solvent at below 50° C.; and (e) collecting the pure gabapentin from the mother liquor by filtration; provided that process does not include ion exchange chromatography as a processing step.