5-phenyl-3-pyridazinone derivatives and drug compositions containing the same
CA 2257142 C · Owner: Yamana, Kenjirou · Inventors: Yamana, Kenjirou; Ina, Shinji; Noda, Kyoji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
5-Phenyl-3-pyridazinone derivatives represented by general formula (I) wherein R1 is optionally substituted C1-C8 alkyl C3-C7 cycloalkyl, or indanyl; R2 is , C1-C4 alkyl; R3 is hydrogen optionally substituted C1-C5 alkyl, C3-C7 cycloalkyl or aryl optionally containing a hetero atom; R4 and R5 are each independently hydrogen, C1-C6 alkyl, optionally substituted phenyl or , monocyclic aryl containing a hetero atom; and the broken line refers to a single or double bond, with the proviso that when the line refers to the former, R6 is hydrogen or C1-C6 alkyl.
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 June 6, 1997 and granted November 26, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 6, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 6, 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.