Xanthine derivatives
CA 2092430 A1 · Owner: Smith, David G. · Inventors: Fenwick, Ashley E.; Buckle, Derek R.; Smith, David G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A compound of formula (I) or if appropriate, a pharmaceutically , acceptable salt thereof; or a pharmaceutically acceptable solvate thereof, wherein R1 and R2 each independently represent a moiety of formula (a): -(CH2)m-A, wherein m represents zero or an integer 1, 2 or 3 and A represents a substituted or unsubstituted cyclic hydrocarbon radical; R3 represents NO2 a halogen , atom, a hydroxy group, an alkoxy group or a methyl group substituted with 1 or 2 groups of formula CO2R wherein R in each group, is independently hydrogen or alkyl or a group of formula O-L-A1 wherein L is a bond or a linking group and A1 is a saturated or unsaturated heterocyclic group, or R3 represents a group of …
Read the whole patent
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 23, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 23, 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.