Process for preparing peroxides using mixed anhydrides

Abstract

The invention relates to a process for the preparation of a peracid, perester or diacylperoxide and is characterized in that a mixed anhydride of formula R 1 [C(O)OC(O)OR 2 ] n or [R 3 C(O)OC(O)O] p R 4 is contacted with a hydroperoxide of formula R 5 [OOH] m in the presence of a base, wherein R 1 represents a mono-, di-, tri- or tetravalent C 1 -C 19 hydrocarbon group, optionally containing one or more hetero atoms, n is 1-4, R 2 represents a C 1 -C 20 hydrocarbon group, optionally containing one or more hetero atoms, R 3 represents a C 1 -C 19 hydrocarbon group, optionally containing one or more hetero atoms, R 4 represents a di-, tri- or tetravalent C 1 -C 20 hydrocarbon group, optionally containing one or more hetero atoms, p is 2-4, R 5 represents hydrogen or a mono- or divalent C 3 -C 18 tertiary alkyl or C 2 -C 20 acyl group, in which the tertiary alkyl or acyl group may optionally contain one or more hetero atoms, m is 1 or 2, and if R 5 represents hydrogen, m is 1, provided that if the hydroperoxide is an α,α′-dihydroperoxyperoxide, the reaction is not carried out in an inert two-phase solvent system comprising a polar solvent and an apolar solvent. The invention also relates to a hydroxyperacid, hydroxyperester, and hydroxydiacylperoxide obtainable by said process and the use of said hydroxyperoxides.

1 . A process for preparing a peracid or diacylperoxide, characterized in that a mixed anhydride of formula R 1 [C(O)OC(O)OR 2 ] n  or [R 3 C(O)OC(O)O] p R 4  is contacted with a hydroperoxide of formula R 5 [OOH]m in the presence of a base, wherein 
 R 1  represents a mono-, di-, tri- or tetrasubstituted C 1 -C 19  hydrocarbon group, optionally containing one or more hetero atoms,    n is 1-4,    R 2  represents a C 1 -C 20  hydrocarbon group, optionally containing one or more hetero atoms,    R 3  represents a C 1 -C 19  hydrocarbon group, optionally containing one or more hetero atoms,    R 4  represents a di-, tri- or tetrasubstituted C 1 -C 20  hydrocarbon group, optionally containing one or more hetero atoms,    p is 2-4,    R 5  represents hydrogen or a mono- or disubstituted C 3 -C 18  tertiary alkyl or C 2 -C 20  acyl group, in which the tertiary alkyl or acyl group may optionally contain one or more hetero atoms,    m is 1 or 2, and    if R 5  represents hydrogen, m is 1,    provided that if the hydroperoxide is an α,α′-dihydroperoxyperoxide, the reaction is not carried out in an inert two-phase solvent system comprising a polar solvent and an apolar solvent.    
     
     
         2 . A process according to  claim 1 , characterized in that n is 1 or 2.  
     
     
         3 . A process according to  claim 1 , characterized in that R 1  and R 3  independently represents a linear or branched C 4 -C 12  alkyl or C 6 -C 12  aryl group, said alkyl and aryl groups optionally being substituted with a hydroxy group, a linear or branched C 1 -C 4  alkyl group or a halogen atom.  
     
     
         4 . A process according to  claim 1 , characterized in that R 2  represents a C 3 -C 8  alkyl group or a C 6 -C 12  aryl group.  
     
     
         5 . A process according to  claim 1 , characterized in that a mixed anhydride of formula R 1 [C(O)OC(O)OR 2 ] n  is used.  
     
     
         6 . A process according to  claim 1 , characterized in that R 5  represents hydrogen or a monovalent C 3 -C 18  tertiary alkyl group.  
     
     
         7 . A process according to  claim 1 , characterized in that the base is an alkali metal hydroxide.  
     
     
         8 . A process according to  claim 1 , characterized in that the reaction is carried out at a pH of 5 or higher.  
     
     
         9 . A process according to  claim 1 , characterized in that the reaction is carried out in the absence of an organic solvent.  
     
     
         10 . A process according to  claim 1 , characterized in that the mixed anhydride is prepared by contacting a carboxylic acid of formula R 1 [C(O)OH] n  with a halogen formate of formula XC(O)OR 2  or [XC(O)O] p R 4  in the presence of a base in an aqueous medium, wherein R 1 , R 2 , R 4 , n, and p have the same meaning as defined in  claim 1  and X is a halogen atom.  
     
     
         11 . A process according to  claim 10 , characterized in that a quatemary ammonium phase transfer or tertiary amine catalyst is present.  
     
     
         12 . A hydroxydiacylperoxide obtainable by the process according to  claim 1  wherein R 1  or R 3  represents a C 1 -C 19  hydrocarbon group, optionally containing one or more hetero atoms, substituted with a hydroxy group, n, R 2 , R 4 , and p have the meaning defined above, R 5  represents hydrogen or a mono- or divalent C 2 -C 20  acyl group, said acyl group optionally containing one or more hetero atoms, said acyl group optionally substituted with a hydroxy group, and m is 1 or 2, with the exception of benzoyl hydroxyacetyl peroxide, with the proviso that said hydroxydiacylperoxide does not contain a hydroxyphenyl moiety.  
     
     
         13 . Use of a hydroxyperoxide according to  claim 1  in bleaching, oxidation, epoxidation, chain transfer, radical (co)polymerization, ot (co)polymer modification reactions.  
     
     
         14 . Use of a hydroperoxide according to  claim 1  in the preparation of poly(meth)acrylates.  
     
     
         15 . A hydroxyperacid obtainable by the process according to  claim 12  wherein R 1  or R 3  represents a C 1 -C 19  hydrocarbon group, optionally containing one or more hetero atoms, substituted with a hydroxy group, n, R 2 , R 4 , and p have the meaning defined above, R 5  represents hydrogen, and m is 1.  
     
     
         16 . Use of a hydroxyperoxide according to  claim 13  in bleaching, oxidation, epoxidation, chain transfer, radical (co)polymerization, ot (co)polymer modification reactions.