JPS5760429B

1507920 Esters BASF AG 18 July 1975 [19 July 1974] 30186/75 Heading C2C [Also in Division C7] In electrochemical manufacture of an aromatic or heterocyclic ester by anodic acyloxylation of an aromatic or heterocyclic compound with an alkanoic acid, electrolysis is carried out in the presence of a conducting salt where R1, R2, and R3 are the same or different and are H or alkyl, at least one being alkyl, and R4 is H or C 1 -C 6 alkyl. The aromatic compound may be a benzene derivative, a naphthalene, anthracene, phenanthrene, acenaphthene, acenaphthylene, tetracene, perylene or chrysene; the heterocyclic compound may be quinoline or benzofuran; substituent groups on the aromatics may be alkyl, aryl, alkoxy, aryloxy, halogen, acyloxy, acylamino, cyano, nitro, or sulphonate; examples are given. Alkanoic acids mentioned are formic, acetic, propionic, butyric, valeric, isovaleric, and caproic; said salt may be made by reacting a suitable amine with such acid and may be trimethylammonium formate, acetate or propionate; triethyl ammonium formate, acetate or propionate, tri-n-butylammonium acetate, dimethylammonium formate, acetate or propionate, or diethylammonium acetate. The anode may be graphite, PbO 2 , Pt or Au, and the cathode graphite, Fe, steel or Pb; the electrode spacing may be 0À25-2 mm. and the C.D. 0À1- 30 A/dm.2; a charge of 0À4-1À5 F/mole causes monoacyloxylation, and >2F/mole a higher degree. The electrolyte may comprise 5-60 wt. per cent aromatic or heterocyclic compound, 5-70% alkanoic acid, 1-20% of the salt and 0-50% of an inert co-solvent; everything apart from the product may be removed afterwards by distillation.