Process for preparing gabapentin
CA 2478471 A1 · Owner: Sasson, Sabar · Inventors: Bercovici, Sorin; Sasson, Sabar; Ulanenko, Konstantin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides compositions and methods of preparing gabapentin that includes (a) subjecting cyclohexanediacetic acid monoamide to 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 gabapentin 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 the gabapentin-amine salt; (e) removing the ion exchange resin from the solution; and (f) concentrating the solution to yield gabapentin.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 16, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 16, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 16, 2025.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.