Method for producing dichloromethylpyridines
CA 2085333 A1 · Owner: Katsuyama, Isamu · Inventors: Shimura, Taku; Katsuyama, Isamu; Nasu, Rikuo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a dichloromethylpyridine of the formula (II):, (II), wherein each of R1 R2, R3 and R4 which are independent, of one another is a hydrogen atom, a halogen atom, an alkoxy group or a phenoxy group which may be substituted provided that R1, R2, R3 and R4 are not simultaneously hydrogen atoms, which comprises reacting a trichloromethylpyridine of the formula (I): (I), wherein R1, R2, R3 and R4 are as defined above with a, reducing agent, wherein:, (1) a dialkyl phosphite or a trialkyl phosphite is used as the reducing agent, and the reaction is conducted in the presence of a basic substance and an alcohol solvent, or, (2) a trialkyl phosphine or triphenyl phosphine is …
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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 December 14, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 14, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2014.
- 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.