Chemical Properties
white to brown crystals or needle crystal, soluble in ethanol, ether, diethyl carbonate, insoluble in water, high toxicity, corrosive.
Application
3,5-Dichloroaniline is used in the production of pesticides, dyes and pharmaceuticals. 3,5-Dichloroaniline is an intermediate in the production of fungicides fumonisin, isoxaflutole, vinblastine and myclobutanil.
Preparation
synthesis of 3,5-Dichloroaniline: Add 25% hydrochloric acid and o-nitroaniline in the reaction kettle, turn on the stirring, pass chlorine gas for chlorination at 10-20℃ and negative pressure, after passing chlorine gas, continue to stir for 15min, then filter, and wash the filter cake with water to neutral, that is, 2,4-dichloro-6-nitroaniline.
In another reaction kettle add industrial ethanol, under stirring, then add 2,4-dichloro-6-nitroaniline, add 95% H2SO4 below 40°C, cool to 15°C, add sodium nitrite in batches, after adding sodium nitrite, continue to hold the reaction at 15°C for 4h, then put the material into denitration kettle, slowly heat to reflux temperature 80°C and keep reflux for 2h, then raise the temperature to evaporate ethanol, and then distill the ethanol. Liquid material into the distillation kettle for water distillation, distillation of the resulting oil and water material for stratification, to obtain 3,5-dichloronitrobenzene.
Put a certain amount of water and 3,5-dichloronitrobenzene in the reaction kettle, raise the temperature to reflux under stirring, add a certain concentration of sodium disulfide solution drop by drop in 1h, and keep reflux for 3h, rest stratification, the lower layer of oily material washed with hot water to obtain 3,5-dichloroaniline.
