Preparation of tetrahydropyran-4-carboxylic acid and esters thereof
CA 2104447 A1 · Owner: Goetz, Norbert · Inventors: Kuekenhoehner, Thomas; Borchers, Dirk; Fischer, Rolf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Herstellung of Tetrahydropyran-4-carboxylic acid and Esters Thereof Abstract of the disclosure, A process for the preparation of tetrahydropyran-4-carboxylic acid and esters thereof of the general formula I, (I), in which R1 denotes hydrogen, C1-C6 alkyl, C5-C8 cycloalkyl or aryl, by the reaction of a dihydro-2(3H)furanone of the general formula II (II), in which, R2 denotes hydrogen, C1-C6 alkyl or -CO-R3 and, R3 denotes hydrogen or C1-C6 alkyl with water or an alcohol of the general formula III R1-OH (III), in which, R1 has the aforementioned meaning at temperatures ranging from 200° to 350°C in the presence of a heterogenous acid catalyst, in which use is made of a fixed heterogenous …
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 19, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 19, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 19, 2015.
- 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.