17700-09-3

65078-77-5

General procedure for the synthesis of 2,3-dichloro-6-nitroaniline from 2,3,4-trichloronitrobenzene: 4000 g of chlorobenzene, 10121 g of ammonia (40% by mass) and 2,3,4-trichloronitrobenzene (1:3 by weight with ammonia) prepared in step S1 were pumped into an autoclave. The reaction temperature was raised to 145 °C under stirring conditions and the reaction was held at this temperature for 5 hours. Upon completion of the reaction, the reaction mixture was cooled to room temperature with cooling water. Subsequently, the material was separated by hydraulic filtration until layered. After distillation to recover the chlorobenzene layer, calcium oxide was added to the ammonia layer to convert ammonium ions to free ammonia. Next, the mixture was heated and evaporated and the free ammonia in the vapor was absorbed by water and recycled for the preparation of 2,3-dichloro-6-nitroaniline. The filter cake was washed to neutrality with hot water at a temperature of 40-60 °C and dried to give the target product 2,3-dichloro-6-nitroaniline. The product was analyzed by liquid chromatography with 97.9% purity and 99.2% yield.