高品质3-氯-4-甲基苯胺的制备

Preparation of High-quality 3-Chloro-4-methylaniline

以对硝基甲苯为原料,在75℃-80℃时,以每小时6L的速度通入氯气520分钟,然后用二硫化钠还原,得到282g3-氯-4-甲基苯胺,含量95％,减压精馏:回流比=10:1,真空度=5263Pa,产品含量为99％,精馏收率为91％,总收率为88％(以对硝基氯苯计)。影响氯化反应的主次因素依次为通氯速度、氯化深度、反应温度,通氯速度可有效控制二氯化物的生成。

o-Nitrotoluene was chlorinated by introducing chlorine at 6 L/h for 520min. at 75-80℃; after reduction by Na2S2, 282g 3-chloro-4-methylaniline of 95% purity were obtained. Vacuum distillation gave a product ith a purity of 99% and ayield of 91%; the overall yield was 88% (based on o-nitrochlorobenzene). The factors affecting chlorination were the rate of chlorine flow, degree of chlorination and reaction temperature. Dichloro compounds can be effectively controlled by adjusting the rate of chlorine flow.