Method for synthesizing phthalimide by means of urea choline chloride eutectic

Phthalimide is synthesized at a relatively low temperature by taking phthalic anhydride as a raw material, taking a urea-choline chloride eutectic solvent as a solvent and taking a urea raw material as a catalyst. According to the method, the defect that a solvent such as xylene, kerosene or N, N-dimethylformamide is used in a traditional process is overcome, the solvent urea-choline chloride eutectic solvent can be recycled, and VOCs emission can be reduced through the new process. The phthalimide crude product is filtered, washed with water, and dried to obtain a phthalimide product with certain purity. The process is simple to operate and mild in condition, the decomposition of urea is reduced by low-temperature reaction, the loss of raw materials caused by sublimation of phthalic anhydride and volatilization of urea is avoided, the production cost is reduced, the product yield exceeds 93%, the purity reaches 98% or above, and compared with similar processes, the process has obvioussuperiority. 本发明以苯酐为原料，尿