NOVELTY - Production of chlorfenapyr comprises adding chlorobenzene glycine, trifluoroacetic acid, and 4-dimethylaminopyridine catalyst to an acetonitrile solvent, uniformly stirring, dropping phosphorus trichloride solution, carrying out acylation reaction at 35-45 degrees C, adding 2-chloro acrylonitrile and dimethylformamide (DMF), dropping triethylamine solution, carrying out cyclization reaction at 25-35 degrees C; and carrying out bromination reaction and condensation reaction.    USE - Method for the production of chlorfenapyr (claimed) used as an insecticidal, acaricidal, and nematicidal medicine.    ADVANTAGE - The acylation reaction simplifies the process flow, reduces energy consumption, is environment-friendly, and improves the purity and yield of the product.    DETAILED DESCRIPTION - Production of chlorfenapyr comprises:    (A) adding chlorobenzene glycine, trifluoroacetic acid, and 4-dimethylaminopyridine catalyst to an acetonitrile solvent, uniformly stirring, dropping phosphorus trichloride solution, carrying out acylation reaction at 35-45 degrees C, preserving temperature, reacting at 60-70 degrees C for 4-6 hours, cooling to room temperature, adding 2-chloro acrylonitrile and dimethylformamide (DMF) to dissolve, dropping triethylamine solution, carrying out cyclization reaction at 25-35 degrees C, preserving temperature, and reacting at 60-70 degrees C for 2 to 4 hours to obtain 2-(4-chlorophenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile solution;    (B) reacting with bromine at 45-55 degrees C, preserving temperature, and reacting for 2-5 hours, and removing the solvent and cosolvent under vacuum condition to obtain 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile crude product; and    (C) adding to an alcohol solvent, stirring and dissolving at 55-65 degrees C and at 0-10 degrees C, stirring for 2-5 hours, filtering the separated crystal, and drying to obtain 4-bromo-2(4-chlorophenyl)-5(trifluoromethyl)pyrrole-3-carbonitrile intermediate; and carrying out condensation reaction of 4-bromo-2(4-chlorophenyl)-5(trifluoromethyl)pyrrole-3-carbonitrile intermediate and chloromethyl ethyl ether in solvent ethyl acetate, dropping triethylamine at 20-35 degrees C, heat preservation condensation reacting for 5-8 hours at 60-70 degrees C, removing ethyl acetate, and hydrolyzing at less than 20 degrees C.