Synthesis
Fuming concentrated nitric acid was slowly added dropwise to a solution consisting of 2,3-dichloro-6-trifluoromethyltoluene and concentrated sulfuric acid, with strong stirring, and the reaction temperature was kept at no more than 0C with an ice-salt thermostatic water bath, and the reaction solution became thicker and thicker during the dropwise process, and solids were precipitated. After the dropwise addition was completed, the solution was stirred at 0 C for 3.5 h. At the later stage, the solution became thinner and the color gradually changed to orange. Then the solution was slowly poured into crushed ice with strong stirring, and the white crystals were filtered out immediately after the ice melted, washed with ice water until the effluent was neutral, then drenched with a small amount of ice methanol, and dried under vacuum at 60 to a constant weight, to obtain the target compound 2,3-dichloro-6-(trifluoromethyl)toluene.
