Expired Canadian patentCanada
Production process of optically pure 2-(4-hydroxyphenoxy)-propionic acid compounds
CA 2535039 C · Owner: Cleugh, Ernest Stephen · Inventors: Cleugh, Ernest Stephen
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing optically pure R-hydroxyphenoxypropanoic acid or a salt or ester thereof by reaction of hydroquinone or a salt thereof with an Shalopropanoic acid or a salt thereof in the presence of a mild reducing 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 August 16, 2004 and granted June 26, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 16, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 16, 2026.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 16, 2004
GrantedJune 26, 2012
Term endedAugust 16, 2024
Patent numberCA 2535039 C
Classification (IPC)C07C51/36 +2 more
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.