Sulfonamides
CA 2016142 C · Owner: Westphalen, Karl-Otto · Inventors: Ditrich, Klaus; Mayer, Horst; Fischer, Klaus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sulfonamides of the general formula I, (see formula I) where, R1 is hydrogen or C1-C4-alkyl, R2 is hydrogen or substituted or unsubstituted C1-C6-alkyl; C3-C4-alkenyl; C3-C4-alkynyl or substituted or unsubstituted saturated or singly unsaturated 5- to 7-membered heteroaryl; R3 and R4 are halogen; substituted or unsubstituted C1-C4-alkoxy C1-C4-alkylthio, C2-C6-alkenyl, C2-C6-alkenyloxy C2-C6-alkenylthio, C2-C6-alkynyl, C2-C6-alkynyloxy C2-C6-alkynylthio, C3-C6-cycloalkyl, C3-C6-cycloalkylthio C5-C6-cycloalkenyl, C3-C6-cycioaikoxy, C5-C6-cycloalkenyloxy C5-C6-cycloalkenylthio, phenyl, phenoxy phenylthio, benzyl, benzyloxy or benzyithio; the groups given for R2, or, NR7R8, where 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 May 7, 1990 and granted July 4, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 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.