Deamination In Ethyl Acetate Media

3,5-dichloronitrobenzene is important intermediate and it is the starting material for manufacture of pharmaceuticals, dyes and pesticides. However, the manufacture of 3,5-dichloronitrobenzene in our country generally suffers from the problems, such as low yields and high pollutions which are troublesome to handle with.The synthesis process of 3,5-dichloronitrobenzene was optimized in the article. 2,6-dichloro-4-nitroaniline reacted in ethyl acetate media to give 3,5-dichloronitrobenzene through diazotizatio and reductive deamination in one-pot. Ethyl acetate displayed not only as a solvent for two-phase reaction, but also as a pro-reducing agent. Since EtOH is used as a reducing agent for reductive deamination, the dediazonization reaction was proceeded even in the presence of 5% EtOH generated from EtOAC. The process was satisfactory with little pollution of waste acid and without by-products(e.g. diethyl ether). Several factors including the amount of sodium nitrite, sulfuric and ethyl acetate, concentration of sulfuric, reaction temperature were investigated. Best conditions were found in orthogonal test: 55mmol NaNO₂, 20mmol 2,6-dichloro-4-nitroaniline, reaction temperature 40℃, the amount of 25% H₂SO₄ 60ml, the amount of ethyl acetate 50ml, reaction time 1h, to give 90.2% 3,5-dichloronitrobenzene.