Process for the preparation of optically active .alpha.-hydroxycarboxylic acids
CA 2085634 A1 · Owner: Carstens, Axel · Inventors: Carstens, Axel; Mohrs, Klaus-Helmut; Hoppe, Dieter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of optically active .alpha.-hydroxycarboxylic acids, A b s t r a c t The invention relates to a process for the preparation of optically active .alpha.-hydroxycarboxylic acids characterised in that carbamates are first reacted in the presence of a selective base and of a chelateforming diamine to give a carbanion complex compound this is than dia- or enantioselectively deprotonated then substituted with CO2 and, as a final step the, heterocyclic protective group is eliminated. Le A 28 839 A- Foreign Countries
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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 December 17, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 17, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 17, 2014.
- 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.