Separation of acids from chemical reaction mixtures by means of ionic liquids

Abstract

Process for preparing aminodihalophosphines, diaminohalophosphines, triaminophosphines, phosphorous ester diamides, aminophosphines, diaminophosphines, phosphorous ester amide halides and aminophosphine halides with elimination of an acid in the presence of an auxiliary base, wherein the auxiliary base b) and the acid form a salt which is liquid at temperatures at which the desired product is not significantly decomposed during the process of separating off the liquid salt and c) the salt of the auxiliary base forms two immiscible liquid phases with the desired product or the solution of the desired product in a suitable solvent.

1 - 16 . (canceled)  
     
     
         17 : A method of removing an acid from a reaction mixture, comprising: 
 providing said reaction mixture containing said acid;    reacting said acid and an auxiliary base to form a salt of the auxiliary base; said salt being liquid at temperatures at which a desired product of said reaction mixture is not significantly decomposed during the process of separating off the liquid salt;    forming two immiscible liquid phases, a first phase comprising said salt of the auxiliary base and a second phase comprising said desired product or a solution of said desired product in a solvent;    firstly, distilling off the desired product from the reaction mixture in the presence of the auxiliary base in the protonated form;    then setting free the auxiliary base using a strong base, to obtain a free auxiliary base; and    distilling the free auxiliary base.    
     
     
         18 : A method of removing an acid from a reaction mixture, comprising: 
 providing said reaction mixture containing said acid;    reacting said acid and an auxiliary base to form a salt of the auxiliary base; said salt being liquid at temperatures at which a desired product of said reaction mixture is not significantly decomposed during the process of separating off the liquid salt;    forming two immiscible liquid phases, a first phase comprising said salt of the auxiliary base and a second phase comprising said desired product or a solution of said desired product in a solvent;    firstly, setting free the auxiliary base using a strong base, to obtain a free auxiliary base;    distilling the free auxiliary base in the presence of the desired product; and    then distilling the desired product.    
     
     
         19 : A method of stopping an acid-catalyzed reaction, comprising: 
 neutralizing an acid catalyst in a chemical reaction mixture with an auxiliary base, to form a salt of the auxiliary base; said salt being liquid at temperatures at which a desired product of said reaction mixture is not significantly decomposed during the process of separating off the liquid salt;    forming two immiscible liquid phases, a first phase comprising said salt of the auxiliary base and a second phase comprising said desired product or a solution of said desired product in a solvent.    
     
     
         20 : The method as claimed in  claim 17 , wherein the salt of the auxiliary base has a melting point below 160° C.  
     
     
         21 : The method as claimed in  claim 17 , wherein the salt of the auxiliary base has an E T (30) of more than 35.  
     
     
         22 : The method as claimed in  claim 17 , wherein the base contains at least one nitrogen atom.  
     
     
         23 : The method as claimed in  claim 17 , wherein the base used is selected from the group consisting of compounds of the formulae (Ia) to (Ir),  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein  
         R 1 , R 2 , R 3 , R 4 , R 5  and R 6  are each, independently of one another, hydrogen, C 1 -C 18 -alkyl, C 2 -C 18 -alkyl which may be interrupted by one or more oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups, C 6 -C 12 -aryl, C 5 -C 12 -cycloalkyl or a five- to six-membered, oxygen, nitrogen- and/or sulfur-containing heterocycle,  
         wherein each of the abovementioned radicals may be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or heterocycles.  
       
     
     
         24 : The method as claimed in  claim 17 , wherein the auxiliary base is 1-n-butylimidazole, 1-methylimidazole, 2-methylpyridine or 2-ethylpyridine.  
     
     
         25 : The method as claimed in  claim 17 , wherein the auxiliary base is di-n-butyl-n-pentylamine or 1,5-diazabicyclo[4.3.0]non-5-ene (DBN).  
     
     
         26 : The method as claimed in  claim 17 , wherein the salt of the auxiliary base is soluble to an extent of less than 20% by weight in the desired product or in the solution of the desired product in a suitable solvent.  
     
     
         27 : The method as claimed in  claim 17 , wherein 
 diphosphorous diester amides ([N](R′O)P—O-Z-O—P[N′] (OR″)),    diphosphorous ester diamides ([N][N′]P—O-Z-O—P[N″][N′″]),    bistriaminophosphines ([N][N′]P—[N″]-Z-[N′″]—P[N″″][N′″″]),    or systems of the formula    [N](R′O)P—O-Z-O—P(OR″)(OR′″),    [N][N′]P—O-Z-O—P(OR″)(OR′″) or    [N][N′]P—O-Z-O—P[N″](OR′″)    or systems which are both nitrogen- and carbon-substituted on each phosphorus and have the formula    [N](R′)P—O-Z-O—P[N′](R′″) or    [N](R′)P—[N″]-Z-[N′″]—P[N′](R′″)    or systems of the formula    [N](R′O)P—O-Z-O—P[N′](R′″)    are prepared,    wherein R, R′, R″ and R′″ can be any organic radicals which may be identical or different, [N], [N′], [N″], [N′″], [N″″] and [N′″″] are unsubstituted, monosubstituted or disubstituted amino groups which may be identical or different and Z can be any divalent bridge.    
     
     
         28 : The method of  claim 17 , wherein the preparation is carried out continuously at from 30° C. to 190° C. and a residence time of from 1 second to 1 hour.