Method of making an aromatic polyether composition using phosphazenium salt phase transfer catalysts

Abstract

A method for carrying out a chemical reaction between at least two reactants occupying separate phases within a multiphase reaction mixture has been discovered in which at least one phosphazenium salt is employed as a phase transfer catalyst. The remarkable utility of phosphazenium salts as phase transfer catalysts is illustrated by the preparation of aromatic ethers. The phosphazenium salt phase transfer catalysts are shown to be especially useful in the preparation of aromatic polyethers such as polyether sulfones.

1 . A method for making an aromatic polyether composition, said method comprising contacting in a reaction mixture the salt of at least one aromatic dihydroxy compound with at least one aromatic compound bearing at least two leaving groups, said contacting being carried out in the presence of a phosphazenium salt having structure I 
     
       
         
         
             
             
         
       
       wherein n is an integer from zero to about 10, R 1  and R 2  are independently selected from the group consisting of C 1 -C 20  aliphatic radicals, C 3 -C 20  cycloaliphatic radicals, and C 4 -C 20  aromatic radicals, and wherein said R 1  and R 2  may be linked together form a cyclic structure comprising at least one nitrogen atom, and wherein X −  is selected from the group consisting of monovalent inorganic anions, monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions, and mixtures thereof. 
     
   
   
       2 . The method according to  claim 1  wherein said aromatic dihydroxy compound is selected from the group consisting of bisphenol A, and 4,4′-biphenol. 
   
   
       3 . The method according to  claim 1  wherein said aromatic compound bearing at least two leaving groups has formula XVIII 
     
       
         
         
             
             
         
       
       G is a carbonyl group, or a sulfonyl group; L 2  is independently at each occurrence a fluoro, chloro, bromo, iodo, nitro, or a trifluormethansulfonate group; and “m” and “p” are independently integers from 0-5, wherein not both m and p are zero. 
     
   
   
       4 . The method according to  claim 1  wherein said contacting further comprises heating to a temperature in a range between about 50 and 250° C. 
   
   
       5 . The method according to  claim 1  wherein said contacting further comprises heating in the presence of an inert solvent to a temperature in a range between about 50 and about 250° C. 
   
   
       6 . The method according to  claim 5  wherein said inert solvent is selected from the group consisting of ortho-dichlorobenzene, para-dichlorobenzene, dichlorotoluene, 1,2,4-trichlorobenzene, diphenyl sulfone, phenetole, anisole, veratrole, toluene, xylene, mesitylene and mixtures thereof. 
   
   
       7 . The method according to  claim 1  wherein said phosphazenium salt is present in an amount corresponding to between about 0.1 and 10 mole percent based on the amount of aromatic hydroxy compound initially present in the reaction mixture. 
   
   
       8 . The method according to  claim 1  wherein said salt of at least one aromatic hydroxy compound is of the formula VI:
   R 3 (ZM) k   (VI)   wherein R 3  is a C 5 -C 40  aromatic radical; M is a metal selected from the group consisting of alkali metals, alkaline earth metals, and mixtures thereof; Z is oxygen, sulfur, or selenium, wherein at least one Z is oxygen; and k is 1, 2 or 3.   
   
   
       9 . The method according to  claim 1  wherein said salt of at least one aromatic hydroxy compound is a salt of a dihydroxy aromatic compound having formula VII: 
     
       
         
         
             
             
         
       
       wherein A 1  is independently at each occurrence a C 3 -C 20  aromatic radical; E is independently at each occurrence a bond, a C 1 -C 20  aliphatic radical, a C 3 -C 20  cycloaliphatic radical, or a C 5 -C 20  aromatic radical, a sulfur atom, a sulfinyl group, a sulfonyl group, a selenium atom, or an oxygen atom; and t, s and u are independently integers from 0-10 wherein at least one of t, s and u is not zero. 
     
   
   
       10 . The method according to  claim 1  wherein said salt of at least one aromatic hydroxy compound is a sodium salt. 
   
   
       11 . The method according to  claim 10  wherein said salt of at least one aromatic hydroxy compound is the disodium salt of bisphenol A. 
   
   
       12 . The method according to  claim 1  wherein said aromatic compound comprising at least two leaving groups has formula XV: 
     
       
         
         
             
             
         
       
       wherein Ar 1  is independently at each occurrence a C 3 -C 20  aromatic radical, L 1  is a leaving group independently selected from the group consisting of fluoro, chloro, bromo, iodo, nitro, and organosulfonate groups; B is an activating group, and g is 2 or 3. 
     
   
   
       13 . The method according to  claim 1  wherein said aromatic compound comprising at least two leaving groups has formula XVI 
     
       
         
         
             
             
         
       
       wherein L 1  is a leaving group independently selected from the group consisting of fluoro, chloro, bromo, iodo, and nitro groups; and R 6  is selected from the group consisting of divalent C 1 -C 12  aliphatic radicals, divalent C 3 -C 12  cycloaliphatic radicals, and divalent C 4 -C 30  aromatic radicals. 
     
   
   
       14 . The method according to  claim 13  wherein R 6  is an aromatic radical having structure XVII 
     
       
         
         
             
             
         
       
       wherein Q is a C 1 -C 12  aliphatic radical, a C 3 -C 12  cycloaliphatic radical, a C 4 -C 18  aromatic radical, an oxygen, atom, a sulfur atom, a sulfinyl group, a sulfonyl group, a selenium atom or a bond. 
     
   
   
       15 . The method according to  claim 1  wherein said salt of the aromatic dihydroxy compound is generated in-situ, from an organic compound which is not itself an aromatic dihydroxy compound. 
   
   
       16 . The method according to  claim 1  wherein said aromatic compound comprising at least two leaving groups is selected from the group consisting of compounds having formula XXI and XXII 
     
       
         
         
             
             
         
       
       wherein in each of structures XXI and XXII D is independently at each occurrence a carbonyl group or a sulfonyl group, and L 3  is independently at each occurrence a fluoro, chloro, bromo, iodo, or nitro group.