Chroman derivatives
CA 2261143 A1 · Owner: Yanagihara, Kazufumi · Inventors: Yanagihara, Kazufumi; Yamashita, Toru; Sato, Masayuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to chroman derivatives of formula (I): wherein R1 represents a hydrogen atom, a halogen atom a C1-6 alkyl group, a C1-6 , alkoxy group a C3-6 alkoxymethyl group, etc.; R3 and R4 each independently represent a hydrogen atom, a C1-6 alkyl group etc.; R5 represents a hydroxyl , group or a C1-6 alkylcarbonyloxyl group or forms a bond together with R5; R6 represents a hydrogen atom or forms a bond together with R5; R7 and R8 each independently represent a hydrogen atom a C1-6 alkyl group, a C3-6 cycloalkyl group, a phenyl group, etc.; n is 0 or an integer of 1 2, 3, or 4; W , represents a phenyl group etc.; X represents C=O, CH2, SO2, etc.; Y represents NR17 …
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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 July 25, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 25, 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.