3,4-二甲氧基苯胺的合成

Synthesis of 3,4-Dimethoxyaniline

以3,4-二甲氧基苯为原料。在0-5℃低温条件下,以硝酸和硫酸按比例配成的混酸进 行硝化,反应结束后过滤得到3,4-二甲氧基硝基苯,该步反应的收率有97％。然后以乙醇为溶剂, 雷尼镍为催化剂,在1．6 MPa的氢气压力下,于高压釜中100℃条件下通过催化加氢将3,4-二甲氧 基硝基苯还原为3,4-二甲氧基苯胺。该反应的收率达到90％以上,纯度达到98％以上。

3,4-Dimethoxyaniline was prepared with 3,4-dimethoxybenzene. The 3,4-dimethoxybenzene was nitrated by mixed acid of HNO3-H2SO4 under the reaction temperature of 0-5℃. 3, 4-dimethoxynitroben-zene was obtained by filtration, and its yield reached over 97%. 3,4-Dimethoxynitrobenzene was dissolved in ethanol and reduced to the product 3, 4-dimethoxyaniline using Raney-Ni as catalyst under the hydrogen pressure of 1.6 MPa in an autoclave （100℃）. The yield and purity of 3,4-dimethoxyanline was up to 90% and 98%, respectively.