Pyrazolopyrimidinone antianginal agents
CA 2044748 C · Owner: Bell, Andrew S. · Inventors: Brown, David; Terrett, Nicholas K.; Bell, Andrew S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Compounds of the formula:, (see fig.I) wherein R1 is H, C1-C3 alkyl, C3-C5 cycloalkyl or C1-C3 perfluoroalkyl; R2 is H, C1-C6 alkyl optionally substituted by CH C1-C3 alkoxy or C3-C6 cycloalkyl, or C1-C3 perfluoroalkyl; R3 is C1-C3 alkyl, C3-C6 alkenyl, C3-C6 alkynyl C3-C7 cycloalkyl, C1-C6, perfluoroalkyl or (C3-C6 cycloalkyl)C1-C6 alkyl; R4 taken together with the nitrogen atom to which it is attached completes a pyrrolidinyl, piperidino, morpholino, or 4-N-(R6)-piperazinyl group; R5 is H, C1-C4 alkyl, C1-C3 alkoxy NR7R8 or CONR7R8R6, is H, C1-C6 alkyl, (C1-C3 alkoxy) C2-C6 alkyl hydroxy C2-C6, alkyl, (R7R8N)C2-C6 alkyl (R7R8NCO)C1-C6 alkyl, CONR7R8, CSNR7R8 or C(NH)NR7R8; R7 and R8 are …
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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 June 17, 1991 and granted February 3, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 17, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 17, 2013.
- 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.