Naphthalene derivative and preparation method thereof
CA 2024971 A1 · Owner: Takeyasu, Takumi · Inventors: Takeyasu, Takumi; Hazato, Atsuo; Kato, Yoshinori
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A naphthalene derivative having the formula (I): (I), wherein R1 represents a hydrogen atom a C1-C5 alkyl, group or a non-toxic salt moiety; R2 and R3 independently represent a hydrogen atom or -OR4 where R4 represents a hydrogen atom or a C1-C3 alkyl group;, A represents a group: or , where X1 and x2 represents an oxygen atom or N-OR5 (where R5 represents a hydrogen atom or a C-1-C3 alkyl group), a group:, where Y1 and Y2 independently an oxygen atom or a group N-OR5 (where R6 represents a hydrogen atom or a C1-C3 alkyl group), or a group:, (where n is 0 or 1); and B represents -(CH2)m-, wherein m is an integer of 1 to 8 -(CH2)m1 -O-(CH2)m2 -, wherein m1 and m2 are independently 1 or 2 or, …
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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 September 10, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 10, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 10, 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.