均三甲苯液相空气氧化合成均苯三甲酸

Synthesis of trimesic from liquid phase oxidation of mesitylene by air

研究了在常压下,以醋酸钴和溴化钠为催化体系,均三甲苯液相空气氧化制备均苯三甲酸的反应工艺。利用酸值滴定、红外光谱和液相色谱等表征方法,确定产物为均苯三甲酸。通过对反应器的类型、催化剂、反应温度和时间等因素的考察,确定出该反应的最佳工艺条件为:采用鼓泡反应器,反应温度95℃,反应时间4.5h,n(均三甲苯)∶n(冰醋酸)∶n(醋酸钴)∶n(溴化钠)∶n(无水乙酸钠)=1∶35∶0.2∶0.1∶0.05,其中Co2+浓度为0.094mol/L。在以上反应条件下,均苯三甲酸的收率可达43 56%,酸值为752.39mg/g,纯度为96.46%。

The preparation process of trimesic from mesitylene by air in a liquid phase oxidation under normal pressure with the catalysis of cobalt acetate and sodium bromide was studied. The product was confirmed as trimesic by using acid value titration, IR spectrum and liquid chromatogram. By studying the effects of reaction conditions, such as types of reactors, reaction temperature, reaction time and catalyst, the optimum conditions were given as followings: n(mesitylene):n(acetic acid):n(cobalt acetate):n(sodium bromide):n(sodium acetate) = 1:35:0.2:0.1:0.05; concentration of Co2+ was 0.094 mol/L; the reaction takes place in a bubbling reactor at 95°C for 4.5 h. Under these conditions the trimesic yield can reach 43.56% , with 752.39 mg/g of trimesic's acid value and 96.46% of purity.