Process for producing n,n-disubstituted aminophenol
CA 2136102 C · Owner: Yasuda, Masaaki · Inventors: Nagamatsu, Shigeki; Arase, Tomohiro; Yasuda, Masaaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing N,N-disubstituted aminophenol which comprises the steps of:, obtaining a reaction mixture containing N-substituted aminophenol by reacting a dihydric phenol and an amine; subjecting said reaction mixture to heat treatment so as to thermally decompose quaternary ammonia salt contained in said reaction mixture into a dihydric phenol and an amine, and removing at least said amine by distillation;, separating high-boiling impurities by distillation to separate N-substituted aminophenol; and subjecting said separated N-substituted aminophenol to reduction alkylation using an aldehyde compound. According to the present invention high-purity N,N-, disubstituted aminophenol …
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 17, 1994 and granted December 2, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 17, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 17, 2016.
- 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.