Process for the preparation of bicyclic diketone salts
CA 2424754 C · Owner: Syngenta Participations Ag · Inventors: Luethy, Christoph; Schneider, Hermann
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 process for the preparation of bicyclic 1,3- diketone salts of formula I (see formula I) wherein R1, R2, R3 and R4 are each independently of the others hydrogen or C1- C4alkyl; A and E are each independently of the other C1-C2alkylene which may be substituted once or up to four times by a C1-C4alkyl group and M+ is an alkali metal ion, alkaline earth metal ion or ammonium ion by oxidation of a compound of formula II (see formula II) to a compound of formula III (see formula III) and subsequent conversion to a compound of formula I either in the presence of a base and a catalytic amount of a cyanide or in the presence of an alkali metal alcoholate or …
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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 April 7, 2003 and granted January 4, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 7, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 7, 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.