Process for preparing chlorodifluorobzene
CA 2058294 A1 · Owner: Isc Chemicals Limited · Inventors: Russell, James J.; Wotton, David E. M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
2058294 9113847 PCTABS00007, 1-Chloro-3,4-difluorobenzene an intermediate in the production, of certain quinolone drugs is produced by converting a, chlorofluoro-aniline into the corresponding diazonium fluoborate and, pyrolysing the latter to give the 1-chloro-3,4-difluorobenzene. 5-Chloro-2-fluorophenyldiazonium fluoborate is a new 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 March 15, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 15, 2013.
- 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.