1-(2,3-dichlorophenyl)-5-iodo-3-(trifluoromethyl)-1H-pyrazole → 1-(2,3-dichlorophenyl)-3-(trifluoromethyl)-1H-pyrazole-5-carbonitrile

To a stirred solution of 1-(2,3-dichlorophenyl)-5-iodo-3-(trifluoromethyl)-1H-pyrazole (11.1 g, 27.58 mmol, 1.0 eq) in NMP (50 mL) was added CuCN (2.39 g, 27.58 mmol, 1.0 eq.) and heated to 200° C. for 2 h. The reaction mixture was passed through a celite pad and washed with excess of ethyl acetate. The filtrate was washed with water and the ethyl acetate layer was separated, dried (Na2SO4), and the solvent evaporated. The resulting residue was purified by CC using ethyl acetate/PE (1:9) to get 1-(2,3-dichlorophenyl)-3-(trifluoromethyl)-1H-pyrazole-5-carbonitrile (5.02 g, crude, yellow solid).