Cyclopentenones, process for preparing the same, and the use thereof
CA 2263563 C · Owner: Takara Holdings Inc. · Inventors: Sagawa, Hiroaki; Enoki, Tatsuji; Nishiyama, Eiji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing 4,5-dihydroxy-2-cyclopenten-1-one represented by formula (1), characterized by heat-treating at least one member selected among: (a) uronic acids or uronic acid derivatives; (b) sugar compounds containing uronic acids and/or uronic acid derivatives; and (c) sugar compound-containing materials containing uronic acids and/or uronic acid derivatives.
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 1, 1997 and granted December 30, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 1, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 1, 2019.
- 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.