An improved process for making o,s-dimethyl phosphoramidothioate
CA 2254516 A1 · Owner: Bayer Corporation · Inventors: Jelich, Klaus; Smith, Donald K.; Prasad, Vidyanatha A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a method for making O,S-dimethyl phosphoramidothioate. In accordance with the present process O,O-dimethyl phosphoramidothioate is isomerized in the presence of a catalyst at a temperature of from about 35°C to about 45°C to form a mixture containing O,S-dimethyl phosphoramidothioate and the resultant mixture is lagered at a temperature of from about 35°C to about 45°C for about 3 to 6 hours. The total time for both steps is at least about 4 hours.
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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 November 25, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 25, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 2020.
- 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.