Process for the preparation of substituted pyridines
CA 2279796 C · Owner: F. Hoffmann-La Roche Ag · Inventors: Klinkhammer, Uwe
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is concerned with a novel process for the carbamoylation of substituted pyridines especially with a process for the preparation of compounds of formula I (see formula I) wherein R4 to R8 represent hydrogen lower-alkoxy or halogen; or optionally salts thereof.
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 August 6, 1999 and granted September 30, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 6, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 6, 2021.
- 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.