Diastereomerically pure intermediates and their use in the preparation of (r)- or (s)-ketoprofen
CA 2075776 A1 · Owner: Arlt, Dieter · Inventors: Arlt, Dieter; Schroeder, Georg
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to novel diastereomerically pure esters of ketoprofen of the formula: Ia Ib, (S-ketoprofen) (R-ketoprofen), (wherein: R1 is , in which, R2 is alkyl, cycloalkyl benzyl or phenyl;, Y is alkoxy, cycloalkoxy benzyloxy, phenoxy or amino, substituted by alkyl cycloalkyl, benzyl or phenyl, or, R1 is a group - R3 is alkenyl optionally substituted by alkyl and, X is oxygen or imino substituted by alkyl benzyl or, phenyl), to processes for their preparation by asymmetric ketene addition and to their use in the preparation of (R)- or (S)ketoprofen.
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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 August 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 11, 2014.
- 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.