Preparation of cis-4-o-protected-2-cyclopentenol derivatives
CA 2216245 C · Owner: Aventis Pharmaceuticals Inc. · Inventors: Hay, David A.; Curran, Timothy T.; Evans, Jonathan C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a novel process for preparing cis-4-Oprotected-substituted-2-cyclopentenol derivatives comprising (a) dissolving a , 4-O-protected-2-cyclopentenone in a suitable organic solvent; and (b) treating the solution with a suitable Lewis acid and a suitable reducing agent at a temperature of from about -100 ~C to about 20 ~C. The cis-4-O-protectedsubstituted-2-cyclopentenol derivatives are useful intermediates in the preparation of various cyclopentanyl and cyclopentenyl purine analogs which are useful as immunosuppressants and in the preparation of various prostaglandins.
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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 March 1, 1996 and granted October 8, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 1, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 2018.
- 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.