Process for preparing tetrahydrofuran
CA 2064561 A1 · Owner: Davy Mckee (London) Limited · Inventors: Tuck, Michael William Marshall; Hiles, Andrew George
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Separation of tetrahydrofuran (THF) from a mixture containing water, THF and a lower alkanol such as ethanol or methanol is, achieved by distillation in two zones the vaporous mixture from the, first zone being condensed and redistilled at a higher pressure in the second zone. Substantially pure THF is recovered from a lower part of the second zone, whilst the vapour from the top of the second zone is combined with the vapour from the first zone prior to condensation and the resulting condensate forms the liquid feed to the second zone. The process is suitable for recovering THF from complex reaction mixtures, containing also butane-1,4-diol and gamma-butyrolactone, obtained by …
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 27, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 27, 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.