A process for the preparation of 4-aminodiphenylamine
CA 2265159 A1 · Owner: Giera, Henry · Inventors: Giera, Henry; Ooms, Pieter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
4-Aminodiphenylamines are prepared by hydrogenating nitrosobenzene or mixtures of nitrosobenzene and nitrobenzene with hydrogen in the presence of fluorides and, heterogeneous catalysts in inert aprotic solvents at temperatures from 0 to 200°C and, pressures from 0.1 to 150 bar.
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 10, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 10, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 10, 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.