Continuous process for preparing optically pure (s)-3,4-dihydroxybutyric acid derivatives
CA 2338757 A1 · Owner: Yu, Ho Sung · Inventors: Yu, Ho Sung; Chun, Jong Pil; Roh, Kyoung Rok
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a continuous process for preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives expressed by Formula (1) and more particularly, to the continuous process which enables preparing optically pure (S)-3,4-dihydroxybutyric acid derivatives economically in large quantities, by: (a) preparing .alpha.-(1,4) linked oligosaccharide having adequate sugar distribution by reacting amylopectin which is easily available from natural product with enzyme under a specific condition; and (b) performing oxidation by running basic anion exchange resin with an oxidant to give (S)-3,4-dihydroxybutyric acid-anion exchange resin complex dissociating , the …
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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 July 23, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 23, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 23, 2021.
- 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.