Method for the production of 2,6-dichloro-5-fluoronicotinonitrile and the chemical compound 3-cyano-2-hydroxy-5-fluoropyride-6-one-monosodium salt and its tautomers
CA 2285365 A1 · Owner: Griehsel, Bernd · Inventors: Steffan, Guido; Griehsel, Bernd; Sattler, Andreas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to 2,6-dichloro-5-fluoronicotinitrile which can be advantageously obtained by reacting 3-cyano-2-hydroxy-5-fluoropyride-6-one and/or its tautomers and/or its salts and/or their tautomers with phosphorus trichloride and chloric gas in a solvent with addition of a basic catalyst at temperatures between 30 and 300 ~C, and then by hydrolysis. The 3-cyano-2hydroxy-5-fluoropyride-6-one-monosodium salt which can be used is a new chemical compound that is easy to obtain from 3-cyano-2-hydroxy-5-fluoropyride- 6-one and/or its tautomers by reaction with alcoholate and precipitation with a moderately weak acid.
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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 19, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 19, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 19, 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.
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.