无水四甲基吡嗪工艺改造

Technological Transformation of Anhydrous Tetramethylpyrazine

研究了无水四甲基吡嗪工艺的改造问题。通过对现有工艺的分析和评估,对利用乙偶姻合成2,3,5,6-四甲基吡嗪的过程进行了研究,考察了不同反应温度、时间、催化剂加料方式,脱水剂的选择等。结果表明:乙偶姻、乙酸铵反应初期温度60℃。反应时间控制在2 h时,2,3,5,6-四甲基吡嗪总收率可达到79%以上,脱水剂则用无水乙醇为溶剂,无水四甲基吡嗪熔点可达到85℃。本研究通过实验验证对比结果显示,经过改造后无水四甲基吡嗪的工艺性能得到了明显提升。

The modification problem of anhydrous tetramethylpyrazine process was studied.Through the analysis and evaluation of existing processes,the process of synthesizing 2,3,5,6-tetramethylpyrazine using acetoin was studied.Different reaction temperatures,times,catalyst feeding methods,and the selection of dehydrating agents were investigated.The results showed that the initial temperature of the reaction between acetoin and ammonium acetate was 60℃.When the reaction time is controlled at 2 hours,the total yield of 2,3,5,6-tetramethylpyrazine can reach over 79%,and anhydrous ethanol is used as the solvent as the dehydrating agent.The melting point of anhydrous tetramethylpyrazine can reach 85℃.This study demonstrated through experimental verification that the process performance of anhydrous tetramethylpyrazine was significantly improved after modification.