Method of producing n-alkylaminophenols
CA 2019059 A1 · Owner: Tanaka, Michio · Inventors: Kurano, Yoshito; Tanaka, Michio; Kawamura, Masato
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed an improvement in the production of an N-alkylaminophenol which comprises: the reaction of a divalent phenol with an alkylamine to provide a reaction mixture and recovering the N-alkylaminophenol from the reaction mixture, the improvement comprising; (a) adding an aqueous solution of an acid to the reaction mixture to provide a two-phase mixture composed of an aqueous phase which contains a water soluble acid salt of the resultant N-alkylaminophenol and an organic phase which contains an unreacted divalent phenol: (b) separating the unreacted divalent phenol as an organic solution by extraction of the two-phase mixture with an organic solvent, to leave an aqueous …
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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 June 15, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 2012.
- 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.