Benzopyrans
CA 1250584 A · Owner: Fisons Plc · Inventors: Gould, Kenneth J.; Suschitzky, John L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
84/02557/N America), There are provided benzopyrans of formula I I, wherein an adjacent pair of R5, R6, R7 and R8 represent the chain -X-CR12R13-CR14R15-Y-in which the chain is substituted by -A1E1, X represents CR10R11 or a single bond Y represents O, S or CR16R17, and, (a) R10 and R12 together form a single bond or (b) R12 and R14 together form a single bond or, (c) R10, R12 and R14 each represent hydrogen; and the remainder of R10, R11, R12, R13, R14 R15, R16 and R17, which may be the same or different, independently represent hydrogen alkyl, NR21COR22, CN or CnHxF(2n+1-x); in addition a, geminal pair of R10, R11, R12, R13, R14 R15, R16, and R17 together with the carbon atom to which …
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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
- Granted February 28, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 28, 2006.
- 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.