Benzopyran compounds, processes for their production and pharmaceutical compositions
CA 2022882 A1 · Owner: Ishizaka, Yoshihiro · Inventors: Sanai, Kazuko; Ishiyama, Nobuo; Murai, Takeshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A compound of the formula (I): (I), or a pharmaceutically acceptable salt thereof wherein:, R1 is a hydrogen atom, a substituted or unsubstituted C1-6 alkyl group, a C2-6 alkenyl group a C2-6 alkynyl, group or a R7-CO- group (wherein R7 is a C1-6 alkyl group a phenyl group, a C2-6 alkenyl group which may be substituted by a phenyl group, or a C1-6 alkoxy group) R2 is a hydrogen atom, a substituted or unsubstituted C1-8 alkyl group, or a phenyl group;, R3 is a hydrogen atom and R4 is a hydroxyl group, or, R3 and R4 together form a bond; each of R5 and R6 is a C1-4 alkyl group; and Y is a cyano group, a halogen atom, a nitro group a, C1-6 alkyl group, a C2-6 alkynyl group a C1-6, …
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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 8, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 8, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 8, 2012.
- 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.