To a 25 mL Schlenk tube equipped with a magnetic stirrer were sequentially added CuCl (0.05 mmol, 5 mol%), DABCO (0.10 mmol, 10 mol%) and 4-HO-TEMPO (0.05 mmol, 5 mol%). Subsequently, a solution of acetonitrile (2 mL) with 4-trifluoromethoxybenzyl alcohol (1 mmol) and ammonia (25-28%, 3 mmol, 3.0 equiv) was added. The reaction mixture was stirred at room temperature for 24 h under balloon protection. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the mixture was diluted with water and extracted with ethyl acetate. The organic layers were combined and dried with anhydrous magnesium sulfate. After concentration under reduced pressure, the crude product was purified by column chromatography to give p-trifluoromethoxybenzonitrile.
