Alcohol-ester separation by reaction with acetate
CA 2055460 C · Owner: Eastman Chemical Company · Inventors: Boaz, Neil Warren
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for the isolation of an enantiomerically enriched alcohol from a first mixture of an enantiomerically enriched 1-arylsulfonate-2-hydroxy-3-butene and an enantiomerically enriched 1-arylsulfonate-2-acyloxy-3-butene. The process includes the steps of: (a) contacting the mixture with a reagent capable of reacting with said 1-arylsulfonate-2-hydroxy-3-butene to remove the arylsulfonate group and produce a mixture of dihydroxybutene monoesters thereby forming a second mixture containing said dihydroxybutene monoesters and unreacted enantiomerically enriched 1-arylsulfonate-2-acyloxy-3-butene; (b) contacting the second mixture with reagents capable of hydrolyzing all of 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 March 28, 1991 and granted April 1, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 28, 2013.
- 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.