Process for cyclopentadiene substitution
CA 2204202 A1 · Owner: Dsm N.V. · Inventors: Green, Richard; Gruter, Gerardus Johannes Maria; Van Beek, Johannus Antonius Maria
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of a substituted cyclopentadiene compound, comprising the reaction of a halide of a substituting compound in a mixture of the cyclopentadiene compound and an aqueous solution of a base in the presence of a phase transfer catalyst wherein during the reaction the quantity of base relative to the cyclopentadiene compound is at any moment between 5 and 30 mol/mol.
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 May 1, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 1, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 2019.
- 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.