Process for dehydrating corticosteroid intermediates
CA 2069645 A1 · Owner: Carruthers, Nicholas · Inventors: Carruthers, Nicholas; Garshasb, Sohaila
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing oxazoline corticosteroid intermediates of formula (V) wherein R1 represents hydrogene (H) loweralkyl, phenyl or phenylalkyl; R4 represents H or loweralkyl preferably, methyl having either the .alpha. or .beta. stereochemistry; and R9 represents hydrogen, fluoro, chloro or loweralkyl. The process comprises contacting a compound of formula (III) herein with (A), Vilsmeier reagent, followed by acid hydrolysis to yield the compound of formula (V); or alternatively (B) an acid having a pKa, of less than 5 to yield the compound of formula (V).
Read the whole patent
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, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 26, 2012.
- 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.