Novel benzopyran derivatives
CA 2275166 C · Owner: Kim, Ju Su · Inventors: Lim, Hyun Suk; Nishimoto, Masahiro; Kim, Myung-Hwa
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 a novel benzopyran derivative having antiestrogenic activity. More specifically the present invention relates to a , novel benzopyran derivative represented by formula (I) and pharmaceutically acceptable salt thereof, in which <o>-----</o> represents a single bond or a double bond; R1 and R2 independently of one another represent hydrogen hydroxy or OR group, wherein R represents acyl or alkyl; R3 represents hydrogen, lower alkyl or halogeno lower alkyl provided that when <o>-----</o> , represents a double bond R3 is not present; R4 represents hydrogen or lower alkyl; A represents a group of formula (a) (b), (c) or (d); R5, R6 and R7 , independently of …
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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 December 13, 1997 and granted July 22, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 13, 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.