Process for preparing trihydrocarbyl (2,5- dihydroxyphenyl) phosphonium salts
CA 1082741 A · Owner: The Dow Chemical Company · Inventors: Duquette, Lawrence G.; Doorakian, George A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is directed to a process for preparing tri-substituted (2,5-dihydroxyphenyl)phosphonium salts of the formula, The process is characterized by reacting together (a) a phosphine of the formula R1R2R3P wherein R1 R2 and, R3 are each independently hydrocarbyl or inertly-substituted hydrocarbyl groups of from 1 to 20 carbon atoms; (b) para-benzoquinone; and (c) a protic acid of the formula H?A?, wherein A? is an inert anion in a, lower alkanol of from 1 to 4 carbon atoms 1,2-ethylene, glycol, 1,2-propylene glycol diethylene glycol, di-, propylene glycol triethylene glycol, tripropylene, glycol a lower alkyl (C1-C4) ether of said glycols or, a mixture thereof. The reaction is …
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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
- Granted July 29, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 29, 1997.
- 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
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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.