Esterification of Chloroacetic Acid and Alcohols Catalyzed by Cupric p-Tolenesulfonate

Copper p-tolenesulfonate was synthesized and characterized by TG and FTIR. It was employed as the catalyst in the esterification of chloroacetic acid with isopropanol. The molar ratio of isopropanol and chloroacetic acid, the amount of catalyst, the amount water-carrying agent (cyclohexane) and reaction time were observed to influence the reaction results clearly. Under the conditions of 0.167 mol chloroacetic acid, the 1.1:1molar ratio of isopropanol to chloroacetic acid, 1.0 molar percentage of catalyst in chloroacetic acid, 2.5 h reaction time, 2.5 mL cyclohexane and reaction temperature 85-90℃, the yield of reaction was 97.0%. Compared with some Lewis acids such as SnCl4, copper p-tolenesulfonate exhibited higher catalytic activity and could be easily separated from the reaction mixture after reaction. After the catalyst was reused 8 times, the yield of isopropyl chloroacetate was 94.6%. Copper p-tolenesulfonate also exhibited high catalytic activity in the esterification of chloroacetic acid with other alcohols. In most cases, the yield of chloroacetate was higher than 90%.