Method for preparing 4-methyl-biphenyl derivatives
CA 2265559 C · Owner: Sanofi-Aventis · Inventors: Dormoy, Jean-Robert; Castro, Bertrand; Alami, Mouad
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns a method for preparing 4-methyl-biphenyl derivatives of general formula (I) in which R represents a protected cyano or tetrazolyl group of formula (a) in which R¿1? located at position 1 or 2 of the tetrazolyl group represents one protecting group characterised in that one halobenzene of formula (II) in which Hal represents one halogen atom and R represents the same as before is reacted with a p-tolymagnesium halide in the presence of a polyether linear or branched, and a catalyst containing a transition metal.
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 September 17, 1997 and granted June 3, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 17, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 17, 2019.
- 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.