Process for the preparation of 3,4'-dichlorodiphenyl ether
CA 2031444 A1 · Owner: Papenfuhs, Theodor · Inventors: Hess, Reiner; Schubert, Hans; Papenfuhs, Theodor
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 3,4'-dichlorodiphenyl ether, A process for the preparation of 3,4'-dichlorodiphenyl ether from 1,3-dichlorobenzene and 4-chlorophenol which, comprises mixing 1 mol of 4-chlorophenol with about 2 to about 6 mol of initially introduced 1,3-dichlorobenzene and about 1 to about 3 mol of potassium carbonate in about 1 to about 5 mol of a dipolar aprotic solubilizer which boils above l60°C, at temperatures of about 160°C to about 190°C with stirring, then adding about 0.0l to about 1 mol-% of basic copper carbonate of the formula Cu(OH)2?CuCO3?0.5 H2O and heating with stirring to about 170 to about 173°C while removing the water formed by distillation, then …
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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 December 4, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 4, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2012.
- 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.