Acetone → 1,3,4-Triphenyl-1H-1,2,3-triazolium hexafluorophosphate

Participants

Reaction Steps

To a stirred suspension of triazene 8c (591 mg, 3 mmol) and phenylacetylene 9a (6604, 6 mmol) in dry dichloromethane (10 mL) in the dark at −78° C. is added tert-butyl hypochlorite (500 μL, 4.4 mmol), upon which the mixture instantly darkens. The mixture is stirred overnight as it is slowly allowed to warm to room temperature. Acetone (10 mL), and potassium hexafluorophosphate (550 mg, 3 mmol) are added to the mixture, and stirring is continued at room temperature for ca. 1 hour. The mixture is then filtered, and the solid residue is washed with acetone and dichloromethane. The collected filtrate is evaporated under reduced pressure. Diethyl ether is then added, and the mixture is vigorously triturated for ca. 1 hour, with occasional scratching of the glass surfaces to ensure efficient mixing. Filtration and washing with copious quantities of diethyl ether afford, after drying under vacuum, triazolium salt 10ca as an off-white solid (1.07 g, 81%). Analytical samples were obtained after recrystallization by vapor diffusion of diethyl ether in an acetonitrile solution of 10ca. 1H-NMR (CD3CN, 300 MHz): δ=9.13 (s, 1H), 8.05 (dd, J=7.1, 3.5 Hz, 2H), 7.79-7.70 (m, 4H), 7.65-7.59 (m, 5H), 7.52-7.46 (m, 4H). 13C-NMR (CD3CN, 75 MHz): δ=145.1, 136.1, 135.1, 133.5, 133.4, 133.0, 131.7, 131.3, 130.5 (2), 128.4, 127.0, 123.3, 123.0. HR-MS (ESI): Calcd. for C20H16N3 [M+]: 298.1339. found 298.1341.

Provenance & Evidence