Process for preparing optically active 2-oxoimidazolidine derivatives
CA 2004606 C · Owner: Kubota, Hitoshi · Inventors: Kubota, Hitoshi; Hayashi, Kimiaki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are a process for preparing an optically active 2-oxoimidazolidine derivative of the formula: (I), wherein R1 represents hydrogen atom or a lower alkyl group, according to the process described in the specification; and a 3-acyl-2-oxoimidazolidine-4-carboxylic acid ester derivative having (S, R) configuration of the formula: wherein R2 represents a tert-butyl group or a benzyl group, and R3 represents a lower alkyl group or an aryl group.
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 December 5, 1989 and granted January 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 5, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 5, 2011.
- 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.