Preparation of unsaturated ketones
CA 2026779 C · Owner: Aristech Chemical Corporation · Inventors: Pugach, Joseph; Salek, Jeffrey S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Unsaturated ketones are produced from ketones and paraformaldehyde under mild reaction conditions utilizing a catalyst comprising a halogen acid salt of a secondary amine and a small amount of a carboxylic acid. Temperatures of 120-150°C and pressures of 775-1135 kilopascals are preferred. Di-unsaturated ketones such as divinyl ketone may also be produced; if the starting ketone already has an unsaturated group a second, unsaturated group will be produced.
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 May 21, 1990 and granted December 30, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 21, 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.