Isomerization process
CA 2228990 A1 · Owner: Wildermann, Angela · Inventors: Wildermann, Angela
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the catalyzed isomerization of a Z-isomer of a vitamin A compound or of a mixture of several of such isomers into a mixture of the corresponding all-E- and 13-Z-isomers of this vitamin A compound comprises using nitrogen monoxide or a gas mixture containing nitrogen monoxide as the isomerization catalyst. Moreover the isomerization, process is conveniently effected in a polar or apolar organic solvent at temperatures up to about 200°C and in such a manner that the catalytic contact with nitrogen monoxide is effected by introducing nitrogen monoxide or a gas mixture containing nitrogen monoxide e.g. with nitrogen, into the, (optionally dissolved) vitamin A compound to be …
Read the whole patent
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 February 9, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 9, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 9, 2020.
- 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.