Process for the preparation of bis-(ethoxycarbonylamino) toluenes and for the preparation of diisocyanatotoluenes therefrom
CA 2072034 A1 · Owner: Schieb, Thomas · Inventors: Schieb, Thomas; Wershofen, Stefan; Heitkamper, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Mo3746, A PROCESS FOR THE PREPARATION OF BIS-(ETHOXYCARBONYLAMINO)TOLUENES, AND FOR THE PREPARATION OF DIISOCYANATOTOLUENES THEREFROM, ABSTRACT OF THE DISCLOSURE A process for the preparation of bis-(ethoxycarbonylamino)-toluenes in which a diaminotoluene is reacted with diethylcarbonate in the presence of a catalyst at 100 to 300°C with simultaneous or subsequent removal of the alcohol formed. The diethylcarbonate being used in an at least 5-times molar excess based on the amino groups of the diaminotoluene. The bis-(ethoxycarbonylamino) toluenes formed are isolated in the form of crystals of great purity obtained after cooling of the reaction mixture. The resulting …
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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 June 23, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 23, 2014.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.