Process for the preparation of 2,3,4,5,-tetrafluorobenzene derivates
CA 2247231 A1 · Owner: Neuner, Otto · Inventors: Lui, Norbert; Bielefeldt, Dietmar; Holzbrecher, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
2,3,4,5-tetrafluorobenzene derivatives can be obtained in a particularly advantageous manner by reacting the corresponding chloro-benzene or (chloro fluoro)-benzene, derivatives with a fluoridating agent in the presence of a solvent and a catalyst at elevated temperature. which comprises carrying out the reaction initially under temperature and pressure conditions such that the respective 2,3.4,5-tetrafluoro-benzene derivative continuously distills off through a column and subsequently, setting temperature and pressure conditions such that residual fractions of the 2,3,4,5tetrafluorobenzene derivative distill off with the corresponding 2.3,4-trifluoro- 5-chloro compound.
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 September 11, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 11, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 11, 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.