A process for the preparation of a dop-containing mixture
CA 2211899 C · Owner: Schill + Seilacher Aktiengesellschaft · Inventors: Rathfelder, Paul; Rieckert, Horst; Dietrich, Jorg
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for the preparation of 2'-hydroxydephenyl-2-phosphinic acid in the form of a commercial mixture with 6-hydroxy-(6H)-dibenzo-(c,e)(1,2)-oxaphosphorine the process being carried out on a commercial scale more simply and more cheaply, than previously as a one-pot reaction without isolating intermediate products and avoiding a distillation step with said process comprising, the steps: (a) o-phenylphenol is added to a mixture of PCl3 and a Lewis acid as a catalyst while simultaneously heating the reaction mixture and the reaction mixture is then fluxed; (b) the resulting reaction mixture is allowed to cool and stirring continuously, is hydrolysed, being mixed …
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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 21, 1996 and granted May 15, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 21, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 2018.
- 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.