Water → HCID 18787018, compound

Participants

Reaction Steps

Tetra n-butyl ammonium fluoride solution (1M in THF, 12.5 ml, 12.5 mmol) was added over 5 minutes to a stirred solution of 4-[3-bromo-4-(trifluoromethoxy)phenyl]-1H-1,2,3-triazole (Description 59) (2.73 g, 8.85 mmol) and dimethyl sulfate (2.10 ml, 22.1 mmol) in THF (50 ml). The mixture was stirred for at room temperature for 1.5 hours, then water (100 ml) and diethyl ether (100 ml) were added. The layers were separated and the aqueous layer was extracted with ether (200 ml). The combined organic layers were washed with water (100 ml) and brine (100 ml), dried (MgSO4) and evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with hexane/EtOAc (75:25 increasing to 50:50) to give 2-methyl-4-[3-bromo-4-(trifluoromethoxy)phenyl]-2H-1,2,3-triazole as a colorless solid (1.50 g, 53%), 1H NMR (250 MHz, CDCl3) δ 8.07 (1H, d, J=2.1 Hz), 7.81 (1H, s), 7.73 (1H, dd, J=8.5, 2.1 Hz), 7.36 (1H, dq, J=8.5, 1.4 Hz), and 4.25 (3H, s), m/z (ES+) 322, 324 (M+1), and 1-methyl-4-[3-bromo-4-(trifluoromethoxy)phenyl]-1H-1,2,3-triazole as a colorless solid (566 mg, 20%), 1H NMR (250 MHz. CDCl3) d 8.12 (1H, d, J=2.1 Hz), 7.80 (1H, dd, J=8.5, 2.1 Hz), 7.78 (1H, s), 7.36 (1H, dq, J=8.5, 1.5 Hz), and 4.17 (3H, s), m/z (ES+) 322, 324 (M+1).

Provenance & Evidence