Preparation of flotation of optically active aliphatic carboxylic acids
CA 2128518 A1 · Owner: Choudhury, Azfar A. · Inventors: Kadkhodayan, Abbas; Choudhury, Azfar A.; Patil, Deepak R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for the separation of enantiomers of a mixture of certain aliphatic carboxylic acids or esters thereof is disclosed. The process involves adding in inert liquid to the reaction solution formed by: (i) forming a salt solution comprising said racemic mixture of a C1 to C6 linear or branched aliphatic carboxylic acid and an organic or inorganic base; (ii) treating said salt solution with less than equimolar equivalents of a chiral organic nitrogenous base; (iii) precipitating from the reaction solution formed in step (ii) the less soluble diastereomeric salt; (iv) addition of a countersolvent to the slurry formed in step (iii); (v) extracting the more soluble …
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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 15, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 15, 2014.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.