杂多酸催化棓酸正丁酯酯化反应研究

Study on preparation of the n-butyl gallate with phosphato-molybdic acid and phosphato-tungstic acid as catalyst

研究了以磷钼酸和磷钨酸为催化剂,由棓酸和正丁醇制备棓酸正丁酯的反应。考察了不同的催化剂用量、醇用量、反应时间对棓酸正丁酯产率的影响。确定了最佳反应条件,棓酸与催化剂磷钼酸的摩尔比为1∶0.0322,丁醇90 mL,反应时间2.5 h;棓酸与催化剂磷钨酸的摩尔比为1∶0.02084,丁醇80 mL,反应时间2.5 h,平均酯化率分别为84.3%和80.2%。在棓酸正丁酯的合成中,采用磷钨酸作催化剂时优于磷钼酸。

The n-butyl gallate was synthesized by esterifying n-butyl alcohol and gallic acid in the presence of phosphato-molybdic acid and phosphato-tungstic acid catalyst. The preparation conditions have been investigated. The optimal reaction conditions are as follows ： the mole ratio of gallic acid to phosphato-molybdic acid was 1 ： 0. 0322, the quantities of butyl alcohol and reaction time were 90 mL and 2.5 h respectively ; the mole ratio of gallic acid to phosphato-tungstic acid was 1 ： 0. 02084, the quantities of butyl alcohol and reaction time were 80 mL and 2.5 h respectively. The average yield of butyl gallate were 84.3% （phosphato-molybdic acid） and 80.2% （ phosphato-tungstic acid） respectively. It is found that the phosphato-tungstic acid catalyst was better than phosphato-molybdic acid catalyst in the esterification of n-butyl gallate.