Highly selective esterification of tert-butanol by acetic acid anhydride over alumina-supported InCl3, GaCl3, FeCl3, ZnCl2, CuCl2, NiCl2, CoCl2 and MnCl2 catalysts

Esterification of tert-butanol by acetic anhydride to tert-butyl acetate over InCl3/Al2O3, GaCl3/Al2O3, FeCl3/Al2O3, MnCl2/Al2O3, CoCl2/Al2O3, NiCl2/Al2O3, CuCl2/Al2O3 and ZnCl2/Al2O3 catalysts have been investigated. The yield of tert-butyl acetate obtained was over 99.5%; when the reaction conditions used were as follows: the molar ratio of tert-butanol/acetic acid anhydride = 1.1, the catalysts/(tert-butanol + acetic anhydride) wt. ratio = 0.026, reaction temperature = 30 °C, and reaction time = 2 h. The esterification activity of the alumina supported metal chloride catalysts is in the following order: InCl3 > GaCl3 > FeCl3 > ZnCl2 > CuCl2 > NiCl2 > CoCl2 > MnCl2.