Production of chirally pure .alpha.-amino acids and n-sulfonyl .alpha.-amino acids
CA 2470111 A1 · Owner: Wyeth · Inventors: Resnick, Lynn
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Methods for production of chirally pure .alpha.-amino acids and N-sulfonyl .alpha.-amino acids are described. An aldehyde and a cyanide salt are reacted with an .alpha.-methylbenzylamine to afford a product. The product reacts with a strong acid, is neutralized, and is extracted. The resulting product is subsequently hydrogenated and hydrolyzed to provide a product which is dissolved in a strong acid to provide a salt of a chirally pure .alpha.-amino acid, which is reacted to provide the chirally pure .alpha.-amino acid. Another method involves mixing ephedrine hemihydrate and an N-sulfonyl .alpha.ethylnorvaline in ethanol at a molar ratio of 1:1; heating the mixture to dissolve 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 November 26, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 26, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 26, 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
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.