Process for preparing (+)-2-(4-chlorophenyl)-3-methyl butanoic acid
CA 2512342 A1 · Owner: Raju, Penumatcha Venkata Krishnam · Inventors: Rao, Attaluri Narasimha; Ishratullah, Khwaja; Babu, Tella Ramesh
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 an environmentally benign process for preparation of (+)2-(4-chlorophenyl)-3-methyl butanoic acid (+ CPA) from its racemic acid, using optically active arylamines like (-) PEA in hydrophilic/hydrophobic organic solvents like butanol propanol etc. as , aqueous mixtures, separating the desired (+) CPA salt mother liquor by , filtration and refining the (+) CPA salt in the same solvent system as used for resolution, recovering the desired acid in high optical purity by extracting with aqueous mineral acid. The mother liquor is concentrated under vacuum and extracted with aqueous mineral acid to obtain undesired (-) CPA which was recovered and recycled …
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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 January 3, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 3, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 3, 2025.
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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.