Method for the anodic alkoxylation of organic substances

Abstract

Organic substrates, such as cyclic ethers, N-substituted amides, ketones, alkyl-aromatic substances and alkyl-heteroaromatic substances can be anodically alkoxylated, especially methoxylated, in the presence of an alcohol. Alkoxylation in the presence of a mediator or in a divided cell using a solid electrolyte is known. The anodic alkoxylation according to the invention is carried out in the absence of a mediator in an undivided electrolytic cell using a diamond anode or gold anode and allows for high yields and a high current efficiency.

1 . A method for the anodic alkoxylation of an organic compound comprising alkoxylating wherein a mixture containing the organic compound and a primary alcohol with 1-4 C atoms is alkoxylated in an unpartitioned electrolytic cell in the presence of a supporting electrolyte salt that is soluble in the mixture but in the absence of a solid polymer electrolyte at an effective cell voltage on an oxidation-resistant anode, and carrying out the anodic alkoxylation in the absence of a mediator, using a diamond film anode or a gold anode.  
   
   
       2 . The method as in  claim 1 , wherein an organic compound selected from the group consisting of cyclic ethers, N-substituted amides, carbonyl compounds, alkyl aromatic hydrocarbons and alkyl heteroaromatic hydrocarbons are anodically alkoxylated.  
   
   
       3 . The method as in  claim 1 , wherein a cyclic ether selected from the group consisting of furans, dihydrofurans, tetrahydrofurans, 1,2-pyrans, 1,4-pyrans and the di- and tetrahydro compounds thereof, and 1,4-pyrones and the di- and tetrahydro compounds thereof is methoxylated or ethoxylated, with at least one C atom bound to the ether oxygen atom in the hydrogenated furans, pyrans and pyrones having a hydrogen atom.  
   
   
       4 . The method as in  claim 1 , wherein an amide selected from the group consisting of lactams with 5-7 ring members, N-acylated saturated and unsaturated N-heterocyclic compounds and open-chain N-alkyl or N,N-diallyl fatty acid amides is methoxylated or ethoxylated, with a carbon atom bound to the nitrogen having at least one hydrogen atom.  
   
   
       5 . The method as in  claim 1 , wherein a ketone with a methyl group or methylene group bound to the carbonyl C atom is methoxylated or ethoxylated.  
   
   
       6 . The method as in  claim 1 , wherein the alkoxylation is carried out in the alcohol that corresponds to the alkoxy group as the solvent and the supporting electrolyte salt used is a tetraalkyl ammonium salt, the anion of which is selected from the group consisting of ClO 4   − , BF 4   − , PF 6   − , SbF 6   − , R—SO 3   −  and R—SO 4   − , wherein R stands for alkyl which can also be halogenated.  
   
   
       7 . The method as in  claim 1 , wherein the anodic alkoxylation is carried out at a voltage in a range from 1-50 V.  
   
   
       8 . The method as in  claim 1 , wherein the supporting electrolyte salt is used in a quantity of 0.1-5 wt %, relative to the organic compound that is to be alkoxylated.  
   
   
       9 . The method as in  claim 2 , wherein the carbonyl compound is a ketone.  
   
   
       10 . The method as in  claim 3 , wherein the organic compound is methoxylated.  
   
   
       11 . The method as in  claim 4 , wherein the organic compound is methoxylated.  
   
   
       12 . The method as in  claim 5 , wherein the organic compound is methoxylated.  
   
   
       13 . The method as in  claim 6 , wherein the alkyl that is halogenated is selected from the group consisting of CF 3 —, CCL 3 -, and CF 3 CH 2 —.  
   
   
       14 . The method as in  claim 7 , wherein the voltage is in the range of from 5 to 25 V.  
   
   
       15 . The method as in  claim 8 , wherein the quantity of electrolyte salt is 0.3-3 wt %.