Process for preparing diketones and keto-acids
CA 2086412 A1 · Owner: Fleischer, Jean C. · Inventors: Jackson, Winston J. Jr.; Walker, Theodore R. Jr.; Fleischer, Jean C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention concerns a process for preparing diketones and keto-acids by reacting a dicarboxylic acid and an aromatic compound in the presence of an alkylsulfonic acid such as methanesulfonic acid and an organic anhydride compound such as methanesulfonic anhydride or trifluoroacetic anhydride. The diketones and keto-acids can be used to prepare polyketones which are useful as molding plastics, coatings, films, fibers, and the like.
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 July 22, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 22, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 22, 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.