20-methyl-substituted vitamin d derivatives
CA 2125476 C · Owner: Schwarz, Katica · Inventors: Thieroff-Ekerdt, Ruth; Kirsch, Gerald; Wiesinger, Herbert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
New 20-methyl-substituted vitamin D derivatives have general formula (3), in which R1 is a hydrogen atom a, hydroxyl group or an alkanoyloxyl group with 1 to 12 carbon atoms or a benzoyloxyl group, R2 is a hydrogen atom or an alkanoyl group with 1 to 12 carbon atoms or a benzoyl group; and R3 is saturated or unsaturated, straight-chain or branched-chain hydrocarbon residue with up to 18 C atoms possibly interrupted and/or substituted by one or several carbocyclic structures (C3-10-cycloalkyl or cycloakenyl residues, the latter having up to 2 double bonds) possibly, substituted by one or several hydroxyl oxo, amino groups, and/or by one or several halogen atoms possibly having one, 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 December 14, 1992 and granted February 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 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.