邻氨基偶氮甲苯合成工艺及邻甲苯胺回收利用研究

Study on process of synthesizing o-aminoazotoluene and reclaimation of o-toluidine

以邻甲苯胺、硫酸、亚硝酸钠为原料,采用重氮化-偶合反应方法制备邻氨基偶氮甲苯。分别考察了硫酸浓度、亚硝酸钠浓度、以及亚硝酸钠与邻甲苯胺的量比等因素对邻氨基偶氮甲苯收率的影响,同时考察了采用一定量回收邻甲苯胺对邻氨基偶氮甲苯收率的影响。结果表明:浓度为36%硫酸溶液、36%亚硝酸钠溶液以及亚硝酸钠与邻甲苯胺的量比为1.1∶1条件下,邻氨基偶氮甲苯的收率达到87%的最高值,纯度为95%;在偶合反应中添加30%～50%的回收邻甲苯胺,产物收率在77%左右。

The o-aminoazotoluene was preparated using o-toluidine, sulfuric acid, and sodium nitrate as raw materials by diazotization and coupling. The influwence of sulfuric acid concentration, sodium nitrate concentrations, and the mole ratio of sodium nitrate and o-toluidine on the reaction was examined. At the same time, the influence of a amount of recovery o-toluldine in the coupling on the reaction was examined. The results showed that the yield of o-aminoazotoluene is 87% , and the purity of o-aminoazotoluene is 95% , when the concentration of the solution of sulfuric acid is 36% , the concentration of the solution of sodium nitrate is 36% , and the mole ratio of sodium nitrate and o-toluidine is 1.1 ： 1. The yield of o-aminoazotoluene is about 77% with addition of 30% - 50% o-toluldine after through recovery and purification in the coupling reaction.