Preparation of alkoxyalkanoic acids
CA 2055804 C · Owner: Shell Canada Limited · Inventors: Fried, Herbert E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a process for the preparation of an alkoxyalkanoic acid of the formula, RO(CH2CHR'O)n CH2CO2 wherein R is an alkyl group of from 1 to 22 carbon atoms R' is, hydrogen or methyl or mixtures thereof (on the individual molecule) and n is an integer of from 1 to 12, or a salt thereof which, process comprises oxidizing the corresponding alkoxyalkanol using an oxidant in the presence of a solubilized stable free radical nitroxide except for di-tertiary nitroxides.
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 November 22, 1991 and granted June 4, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 22, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 22, 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.