Continuous process for the production of optically pure (s)-.beta.-hydroxy-.gamma.-butyrolactone
CA 2499655 A1 · Owner: Kim, Jin-Woong · Inventors: Kwak, Byong-Sung; Kim, Jin-Woong; Koh, Ki-Ho
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a continuous process for the production of optically pure (S)- .beta.-hydroxy-.gamma.-butyrolactone having constantly maintained optical activity, consisting of hydrogenating 2-50 wt% of a substituted carboxylic acid derivative in a solvent using a fixed bed reactor filled with a precious metal catalyst-impregnated inorganic oxide carrier at 50-500 ~C under pressure of 15-5,500 psig at weight-space-velocity of 0.1-10 h-1 in which a molar , ratio of hydrogen to carboxylic acid derivative ranges from 2 to 10. The desired material can be produced in higher optical purity and at higher yield by the current process which is relatively simpler and environmentally safer than …
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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 September 18, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 18, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 18, 2024.
- 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
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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.