General method: iodobenzene (1.2 mmol), 1,2,4-triazole (1.0 mmol), cesium carbonate (2 mmol) and Cu(OAc)2-H2O (0.01 mmol) were dissolved in N,N-dimethylformamide (2 mL) under nitrogen protection. The reaction mixture was stirred at 110 °C for 24 hours. After completion of the reaction, it was cooled to room temperature and the mixture was partitioned between water and ethyl acetate. The organic phase was separated and the aqueous phase was extracted with ethyl acetate. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford the target product 4-phenyl-4H-1,2,4-triazole.
