Process for the preparation of polycyclic compounds
CA 2067552 A1 · Owner: Mitsuhashi, Hiroshi · Inventors: Tanaka, Masahide; Wakamatsu, Takeshi; Mitsuhashi, Hiroshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polycyclic compounds (I) can be prepared in accordance with the following reaction formula: iron , perchlorate, ?, TFA, wherein R1-R8 each represents a hydrogen atom a, hydroxyl group, an alkoxyl group or a substituted or unsubstituted benzyloxy group or neighboring two groups of R1-R8 are coupled together to form an alkylenedioxy group; and A is an alkylene group which may be sub stituted by one or more alkoxycarbonyl groups an, alkenylene group which may be substituted by one or more alkoxycarbonyl groups, or a group represented by any one of the following formulas:, , and . This facilitates the development of processes for the synthetic production of naturally occurring drugs.
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 April 29, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 29, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2014.
- 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.