Preparation of alcohol-extended and amine-extended piperazines
CA 2029428 A1 · Owner: Bowman, Robert G. · Inventors: Hartwell, George E.; Bowman, Robert G.; Molzahn, David C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing alcohol-extended and amine-extended piperazines comprising contacting a difunctional aliphatic alcohol with a reactant amine wherein at least one of the aliphatic alcohol or the reactant amine contains a piperazine moiety in the, presence of a catalyst containing a tungsten heteropoly acid. For example, monoethanolamine reacts with piperazine in the presence of a 12-tungstophosphoric acid catalyst to yield predominately N-(2-aminoethyl)piperazine, which is an amine-extended piperazine. 37,087-F
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 November 7, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 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.