Chromenoneindoles
CA 2520892 C · Owner: Heinrich, Timo · Inventors: Seyfried, Christoph; Schiemann, Kai; Hoelzemann, Guenter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method for the production of compounds of formula (I), wherein R, R1, R2 and R3 have the meaning cited in claim 1 in addition to , compounds , of formula (IV) wherein R and R1 have the meaning cited in claim 1 and are , intermediate products for the production of compounds of formula (I).
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 March 8, 2004 and granted August 21, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 8, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 8, 2026.
- 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.