Improvement On The Synthesis Of 3, 5-Dichloroaniline

3,5-dichloroaniline is important intermediate and it is starting material for manufacture of pharmaceuticals, dyes and pesticides. But at present, the manufacture of3,5-dichloroaniline in China is unsatisfactory with low yield and high pollutions.The synthesis process of 3,5-dichloroaniline is improved in the article. 2,6-dichloro-4-nitroaniline is diazotized and deaminated to give 3,5-dichlorobenzene, then 3,5-dichlorobenzene is reduced by Na2S2 in water. The emphasis of the article is improving on the synthesis of 3,5-dichlorobenzene. Two methods are taken and the two processes are all satisfactory on yield. The yield of 3,5-dichlorobenzene is increased to 62.6% and 79.6% respectively. Many factors which affect the reactions, such as amounts and concentration of sulfuric acid, reaction temperature and time and catalysts have been studied and been optioned.