Diphosphines
CA 2348595 A1 · Owner: Doucet, Henri · Inventors: Carmichael, Duncan; Brown, John Michael; Doucet, Henri
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A non-symmetrical diphosphine of the formula R1R2P-(Z)-PR3R4 wherein Z represents a chain of 2 to 4 carbon atoms which may be substituted which , chain may be saturated or unsaturated and R1, R2, R3 and R4, which may be the same or different, are aliphatic, aromatic or heteroaromatic groups attached to the phosphorus by carbon, nitrogen, oxygen or sulphur such that each phosphorus atom and its substituents independently form a single enantiomer.
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 October 29, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 29, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 29, 2021.
- 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.