Electrochemical alkoxylation of aliphatic ether(s) - using vitreous carbon or platinum anode(s)

摘要

Alkoxylation of aliphatic ethers (I) having at least one alpha-CH atom is effected by electrolysis in an alcohol in the presence of conventional supporting electrolytes, with the improvement that the anode material is vitreous carbon or Pt (esp. vitreous carbon). (I) are pref. of formula R1R2CH-O-CR3R4R5 (where R1 and R5 are H, alkyl or alkoxyalkyl, or R1 + R5 is CH2OCH2, CH2OCH(OR6) or (CH2)n, where R6 is lower alkyl and n is 0-5; and R2-R4 are H or alkyl, provided that the total no. of C atoms in R1-R5 is not more than 18, pref. not more than 8). The alcohol is pref. a 1-4C alkanol (esp. MeOH or EtOH). Prepd. supporting electrolytes are alkali metal and ammonium salts of HF, HBF4, HPF6, HClO4, HSO4Me and p-toluenesulphonic acid. Electrolysis is pref. effected at 0-70 (esp. 20-40) deg.C. The products are useful as intermediates, e.g. for pharmaceuticals. Use of the stated anode materials increases the yield (current efficiency).