Process for preparing enantiomerically pure fluorinated epoxychromans
CA 2130481 A1 · Owner: Smithkline Beecham P.L.C. · Inventors: Turner, Gillian; Bell, David; Fedouloff, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing compounds of formula (B) wherein: one of A1' or A2' represents hydrogen and the other represents a group CF3-Y- wherein Y represents -CF2- > C=O, or -CH(OH)-, or , A1' and A2' are groups convertible to A1 and A2 respectively. Y1 represents -O-, -CH2- or NRO wherein RO is hydrogen, alkyl or alkylcarbonyl; R1 and R2 independently represent hydrogen or alkyl; or R1 and R2 together represent a C2-7 polymethylene moiety; R3 represents hydrogen hydroxy, alkoxy, or acyloxy and R4 is hydrogen or R3 and R4 together represent a bond; which process comprises reacting a compound of formula (C): wherein the variable A1', A2', Y1 R1 and R2 are, as defined above, in the presence …
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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 February 18, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 18, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 18, 2015.
- 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.