Novel benzopyran derivatives
CA 2128603 A1 · Owner: Chugai Seiyaku Kabushiki Kaisha · Inventors: Koga, Hiroshi; Nabata, Hiroyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Benzopyran derivatives represented by formula (I): (I), wherein X represents =O, S, =N-Z, etc. (Z represents a lower alkyl group, etc.); Y represents a substituted amino group, an alkoxy group, an alkylthio group etc. and R1, R2, R3, R4 and R5 each represents a hydrogen atom a lower alkyl group, etc, are disclosed. The benzopyran derivative exhibit K channel opening activities and are widely applicable as antiasthmatics, antiepileptics and the like.
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 January 25, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 25, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 25, 2015.
- 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.