Amidation of pyridines
CA 2245055 C · Owner: F. Hoffmann-La Roche Ag · Inventors: Vogt, Peter; Scalone, Michelangelo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
It has been found that pyridine-2-carboxamides of the formula, (see fig.I), wherein R signifies amino or a residue convertible into amino, and pharmaceutically usable acid addition salts of that carboxamide in which R signifies amino can be manufactured in a simple manner and in good yield by reacting 2,5-dichloropyridine in the presence of a palladium-phosphine catalyst with an alkyne of the formula R1-C~CH III, wherein R1 signifies hydrogen lower-alkyl, trimethylsilyl or the group -(R2)(R3)-COH and R2 and R3 each independently signify hydrogen or lower-alkyl or together signify cyclopentyl or cyclohexyl, oxidizing the resulting alkyne to give 5-chloropyridine-2- -carboxylic acid and …
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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 January 30, 1990 and granted March 25, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 30, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 30, 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.