| abstract |
The title compounds are prepared by reacting (a) a trihydrocarbylphosphine, (b) p-benzoquinone, and (c) a protic acid in a liquid reaction medium comprising a lower alkanol of from 1 to 4 carbon atoms, a 1,2-alkylene glycol, dialkylene glycol or trialkylene glycol or a lower alkyl mono-ether of said glycols. The glycols are either ethylene glycol, propylene glycol, or the indicated oligomers thereof. Methanol is the solvent of choice. As an example, tri-n-butyl (2,5-dihydroxyphenyl)phosphonium chloroacetate was prepared in excellent yields by slowly adding tri-n-butylphosphine, precooled to about 0 DEG C, to a vigorously stirred suspension of p-benzoquinone in a methanol solution of chloroacetic acid at a temperature of approximately -10 DEG C. A precatalyzed epoxy resin was obtained by merely adding the methanol solution of the phosphonium chloroacetate to a liquid epoxy resin (e.g., the diglycidyl ether of bisphenol-A). |