【摘要】 介绍以丁二酮和1,2-丙二胺为原料,经缩合、脱氢芳构化反应合成2,3,5-三甲基吡嗪的新方法.重点考察了脱氢剂组成、脱氢剂用量、溶剂用量等对反应的影响.确定了合成2,3,5-三甲基吡嗪的优化条件为:以无水乙醇为溶剂,投料比为丁二酮∶丙二胺∶脱氢剂∶无水乙醇=1∶0.67∶1.4∶1.31(质量比);缩合反应温度为20~25℃;回流脱氢4 h,2,3,5-三甲基吡嗪的含量达98%以上.更多还原

【Abstract】 A novel method introduce to synthesis 2,3,5-trimethylpyrazine by consendation of biacetyl and 1,2-diaminopropane followed by dehydroarmatization was studied.The composition of dehydrogenation oxidizer,the amount of dehydrogenation oxidizer and solvent were investigated emphatically.The optimum conditions were established as follow: anhydrous ethyl alcohol as solvent,the ratio of biacetyl,1,2-diaminopropane,dehydrogenation oxidizer and solvent is 1∶0.67∶1.4∶1.31(by weight),condensation at 20~25 ℃,and dehydrogenation at refluxing temperature of ethyl alcohol for 4 h,2,3,5-trimethylpyrazine can be obtained with 98% purity.更多还原