1,2,3-三甲氧基苯的绿色合成工艺研究

摘要

采用碳酸二甲酯(DMC)代替传统的有毒有害试剂作为甲基化试剂和以廉价的焦性没食子酸(PA)为原料,在离子液体[ Bmim] Br催化作用下合成1,2,3-三甲氧基苯(TMB).通过单因素和正交试验考察了PA和DMC的摩尔比、催化剂的用量、反应温度以及反应时间等因素对甲基化反应的影响.结果表明:各因素的影响程度为反应温度＞催化剂用量＞物料配比＞反应时间.较佳的工艺条件为PA和DMC摩尔比1∶6,催化剂[Bmim] Br用量相对于PA的摩尔比是1∶1,在160℃下反应7h的产率达92.6％,并通过核磁和质谱对制备的目的产物TMB进行了确证.%1,2,3-Trimethoxybenzene (TMB) was prepared from pyrogallic acid (PA) by the catalysis of ionic liquids [Bmim]Br, with dimethyl carbonate (DMC) as methylating reagent instead of conventional toxic reagents. Some experiments of single-factor test and orthogonal test were conducted to confirm the better reaction conditions by altering the reaction time, the reaction temperature and the mole ratio of PA to DMC. The results show that the effect degree is reaction temperature > catalyst dosage > mole ratio of PA to DMC > reaction time; under the optimized reaction conditions of the reaction temperature 160 ℃, the molar ratio 1:6 of PA to DMC, the reaction time 7 h and the mole ratio 1: 1 of catalyst to PA, the yield of TMB is 92. 6 %. TMB prepared is confirmed by HNMR and GC-MS.