柠檬酸三甲酯的合成

Synthesis of Trimethyl Citrate

以柠檬酸和甲醇为反应原料、硫酸为催化剂,采用直接酯化合成了柠檬酸三甲酯。考察了甲醇重复使用次数、催化剂用量、回流反应时间及原料柠檬酸与甲醇摩尔比对产品收率和酸值的影响。结果表明,在甲醇重复使用3次,催化剂用量1 g,反应时间3 h,原料柠檬酸用量0.2 mol,柠檬酸与甲醇摩尔比1:6的较佳反应条件下,产品收率可达到77.1%,酸值4 mgKOH/g。产物结构通过GC-MS进行确证。

Trimethyl citrate was synthesized by direct esterification using citric acid and methanol as raw materials and sulfuric acid as catalyst. Effects of times repeatedly using methanol, the amount of catalyst, reaction time as well as molar ratio of citric acid to methanol on the yield and acid value of product were studied. The obtained optimum reaction conditions were as follows： times repeatedly using methanol 3, reaction time 3 hours, dosage of catalyst 1 g, n （ citric acid） ： n （methanol） = 1 ： 6 （ when the amount of citric acid was 0.2 mol）. Under the optimum conditions, yield of product was up to 77.1% and acid value was 4 mgKOH/g. The product was identified with GC -MS.