Silver tetrafluoroborate (AgBF4, 19.77 g, 100 mmol) and sodium trifluoromethanesulfinate (CF3SO2Na, 18.73 g, 120 mmol) were dissolved in anhydrous acetonitrile (400 mL) under nitrogen protection. After cooling the reaction mixture to 0°C, triphenylphosphine (Ph3P, 62.95 g, 240 mmol) was slowly added. Subsequently, the reaction mixture was brought back to room temperature and heated to 50°C and maintained at this temperature for 12 hours. Upon completion of the reaction, the mixture was filtered through diatomaceous earth and the filtrate was cooled to -20°C to promote crystallization. After the crystals were sufficiently precipitated, the supernatant was decanted to remove most of the triphenylphosphine oxide. The supernatant was concentrated under reduced pressure to remove the solvent and the residue was washed well with ether and dried under vacuum. Finally, the resulting solid was recrystallized with tetrahydrofuran and benzene to afford silver trifluoromethane thiol (I) (18.60 g, 89% yield).
