Cyclobutane derivatives
CA 2043099 A1 · Owner: Akaba, Hiroshi · Inventors: Kato, Sayuri; Sugawara, Yuka; Ichikawa, Yuh-Ichiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to cyclobutane derivatives represented by the following general formula (1) and physiologically acceptable salts thereof: (1), wherein B represents a nucleic acid base derivative R1, and R2 independently represent hydrogen atom dialkyl-, aminoacyl group, 1,4-dihydro-1-methylnicotinoyl group or substituted phosphoric acid group, provided that either one of R1 and R2 is a group other than hydrogen atom. The compounds of this invention exhibit a high oral absorbability and are metabolized in vivo into the compounds of formula (1a). Accordingly the compounds, of this invention are expectedly useful as antiviral agent.
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 May 23, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 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.