Process for the preparation of pyrazolo¬4,3-d pyrimidin-7-one compounds and intermediates thereof
CA 2354175 A1 · Owner: Harris, Laurence James · Inventors: Devries, Keith Micheal; Allerton, Charlotte Moira Norfor; Negri, Joanna Teresa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is provided for the preparation of compounds of formula (I) herein comprising reacting a compound of formula (II) (III), (IV) or (V) in the , presence of ~ OR3 and a hydroxide trapping agent or in the case of compounds of formula (IV) reacting in the presence of an auxiliary base and a hydroxide trapping agent (i.e. ~, OR3 is substituted by the auxiliary base) wherein X is a leaving group and R1 , to R4 are as defined.
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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 July 26, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 26, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 2023.
- 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.