Method of preparing optically active 4-aryl-2-pyrrolidinones
CA 2070653 A1 · Owner: Zuhse, Ralf · Inventors: Zuhse, Ralf; Mulzer, Johann
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a stereo-selective method for the preparation of (4R)-or(4S)-4-aryl-2-pyrrolidinones of formula (I), in which R1 is hydrogen or a hydrocarbon group with up to 7 carbon atoms which may contain an oxygen atom in the carbon chain and R2 is CI-4 alkyl group as well as, intermediates and a stereo selective method for the preparation of the optically active intermediate compounds.
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 September 27, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 27, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 27, 2013.
- 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.