Process for preparing 3,4-difluoroaniline
CA 2080596 A1 · Owner: Pfizer Limited · Inventors: Braish, Tamim F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing 3,4-difluoroaniline comprising reacting 1-hydroxylamine-3-fluorobenzene with anhydrous hydrogen fluoride in the absence of oxygen. This compound is useful as a starting material for preparation of quinolone antibacterials. 3-Fluoro-1-hydroxylamine may be prepared by hydrogenating 3-fluoro-1-nitrobenzene.
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 April 12, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 12, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 12, 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.