Cyclic synthesis method of nitroaniline chloride

The invention discloses a cyclic synthesis method of nitroaniline chloride. The cyclic synthesis method comprises the following steps: (1) mixing nitroaniline and sulfuric acid, and preheating to a chlorination reaction temperature; (2) respectively inputting the solution obtained in the step (1) and chlorine into a reactor to carry out a chlorination reaction, cooling the material obtained in thereaction to obtain a supersaturated solution, and crystallizing to separate out a supersaturated product namely nitroaniline chloride; and (3) carrying out solid-liquid separation on the material cooled in the step (2), carrying out flash evaporation on the obtained saturated nitroaniline chloride/sulfuric acid solution, recycling hydrogen chloride, and circulating hydrogen chloride to the step (1) to replace sulfuric acid for dissolving nitroaniline, thereby realizing cyclic synthesis of nitroaniline chloride. Product super-saturation precipitation and saturated solution circulation are realized, the proportion of r