超声波相转移催化合成对羟基苯甲酸苄酯

采用超声波相转移催化技术,以四丁基溴化铵为相转移催化剂,先将对羟基苯甲酸和碳酸钾成盐,再使对羟基苯甲酸钾盐、氯化苄在水和二甲苯的二相体系中酯化合成对羟基苯甲酸苄酯。经正交实验确定最佳条件:超声功率160W,超声温度85~90℃,超声时间1h,氯化苄与对羟基苯甲酸摩尔比为2:1,四丁基溴化铵与对羟基苯甲酸摩尔比为0.02:1,二甲苯与水体积比为1:4。产率可达90.3%。

Synthesis of Benzyl p-Hydroxybenzoate by Ultrasonic Phase Transfer Catalysis

By using ultrasonic phase transfer catalysis technique, with tetrabutyl ammonium bromide (TBAB) as phase transfercatalyst, p-hydroxybenzoic acid reacted with potassium carbonate to form potassium p-hydroxybenzoate, then potassium p-hydroxybenzoate reacted with benzyl chloride in two-phase system of water and dimethyl benzene to synthesize benzyl p-hydroxybenzoate.The optimum reaction conditions obtained by orthogonal experiment design were shown as follows: the power of ultrasonic radiationwas 160W, reaction temperature was 85~90℃, reaction time was 1h, the mole ratio of benzyl chloride and p-hydroxybenzoic acid was2:1, the mole ratio of TBAB and p-hydroxybenzoic acid was 0.02:1, and the volume ratio of xylene and water was 1:4. The optimumproduction yield could reach 90.3%.