Improved methods of preparing 4-cyano-4-(substituted indazole)cyclohexane-carboxylic acids useful as pde4 inhibitors
CA 2252344 C · Owner: Caron, Stephane · Inventors: Caron, Stephane
Overview
Its claims, description and drawings are in the Canadian Patents Database.
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An improved process for preparing a compound of Formula (1): comprising:, (a) treating a compound of Formula (la): with an alcohol comprising a compound of Formula (Ib-A) and an acid comprising acompound of Formula (Ib-B): Ra-OH and HX, (lb-A) (lb-B), wherein, R. is selected from the group consisting essentially of hydrogen; (C1-C6) alkyl; phenyl and (C1-C3) alkyl-phenyl wherein said phenyl groups are optionally substituted by one or two substituents selected from the group consisting essentially of -(C1-C4) alkyl; -O(C1-C3) alkyl; Br; and Cl; and, HX is an acid selected from the group consisting essentially of hydrobromic acid; hydrochloric acid; sulfuric acid; sulfonic acid; and aliphatic …
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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 2, 1998 and granted December 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 2, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 2, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.