2,6-二甲基苯胺的合成研究进展

综述了 2 ,6二甲基苯胺合成的研究进展 ,对硝化还原法、甲基化法、氨解法等合成路线及其所用催化剂进行了介绍。硝化还原法是目前主要的合成 2 ,6二甲基苯胺的方法 ,但是铁粉还原法存在产品质量差 ,催化加氢法存在工艺路线不合理等缺点。苯胺甲基化法产品组成复杂 ,选择性差。以 Al2 O3、Pd/C、Pd/Al2 O3Mg O为催化剂 ,采用 2 ,6二甲基苯酚气相氨解法制备 2 ,6二甲基苯胺 ,反应物转化率和产品选择性高 ,是一条理想的合成路线 ,具有工业化前景 ;以 Pd/Al2 O3Mg O为催化剂 ,2 ,6二甲基苯酚的转化率达到 97.9% ,2 ,6二甲基苯胺的选择性达到 79.3 % ;如果副产物 2 ,6二甲基环己胺经蒸馏后循环利用 ,则 2 ,6二甲基苯胺的收率高达 98.3 %

RESEARCH PROGRESS IN SYNTHESIS OF 2,6-DIMETHYLANILINE

The research progress in synthesis of 2,6dimethylaniline was reviewed, and the catalysts used in various synthetic routes were introduced. Although the nitrationreduction method is the main synthetic route of 2,6dimethylaniline now, but the product quality of ironreduction method is poor, and the technique route of catalytic hydrogenation method is irrational. The product selectivity of methylation method is very low. The recent developments in gasphase aminolysis of 2,6dimethylphenol on catalysts Al 2O 3, Pd/C, Pd/ Al 2O 3MgO is an ideal synthetic route and of industrialization prospect because of high conversion of reactants and high selectivity of product. On the catalyst Pd/ Al 2O 3MgO, the conversion of 2,6dimethylphenol attained 97.9%, and the selectivity of 2,6dimethylaniline 79.3%. If the byproduct 2,6dimethylcyclohexylamine is utilized as recycle stock after distillation, the yield of 2,6dimethylaniline can be as high as 98.3%.