Process for the preparation of n-carboxymethyleneanthranilic acid esters
CA 2197046 A1 · Owner: Dierdorf, Andreas · Inventors: Dierdorf, Andreas; Papenfuhs, Theodor; Neumann-Grimm, Doris
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for the preparation of N-carboxymethyleneanthranilic acid esters Process for the preparation of N-carboxymethyleneanthranilic acid esters of the formula (3), (3), by reacting a compound of the formula (1) (1), in which R' is hydrogen or a straight-chain or branched alkyl radical having 1 to 4 carbon atoms and R1, R2, R3 and R4 are identical or different and independently of one another are hydrogen, halogen, NO2 a straight-chain or branched alkyl, alkoxy or halogenated alkyl radical having in each case 1 to 6 carbon atoms with a, glyoxylic acid ester of the formula (2) OHC-COOR (2), in which R is a straight-chain or branched alkyl radical having 1 to 20 carbon atoms phenyl radical …
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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 February 7, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 7, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 7, 2019.
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Timeline
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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.