Production of alkali metal diarylphosphide and cycloalkyldiarylphosphines
CA 2295947 A1 · Owner: Welsh, George W. · Inventors: Welsh, George W.; Layman, William J. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
1) Alkali metal diarylphosphides are formed by mixing triarylphosphine with and preferably introducing triarylphosphine into a two-phase mixture one or , more alkali metals preferably a mixture or alloy of sodium and potassium in , an anhydrous organic liquid diluent in the presence of molecular hydrogen. (2) To form a cycloalkyldiarylphosphine, at least a portion of the reaction mixture formed as in (1) (or alkali metal diarylphosphide recovered therefrom) and cycloalkyl mesylate or tosylate are mixed together and maintained under suitable reaction conditions. Reaction (2) is driven by the presence of residual sodium from reaction (1). Conduct of reaction (2) under a hydrogen …
Read the whole patent
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 26, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 26, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 26, 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.