Phosphorus tribromide → 4-(bromomethyl)-1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole

Participants

Reaction Steps

PBr3 (76 μL, 0.81 mmol) was added to a solution of alcohol 117 (0.210 g, 0.813 mmol) in ether (10 mL) at 0° C. The mixture was stirred at room temperature for 2 h, then cooled to 0° C., quenched with ice, and partitioned between Et2O and water. Column chromatography of the organic portion on silica gel (eluting with CH2Cl2) gave 4-(bromomethyl)-1-[4-(trifluoromethoxy)phenyl]-1H-pyrazole (118) (0.212 g, 81%) as a white solid: mp 50-51° C.; 1H NMR (CDCl3) δ 7.94 (d, J=0.5 Hz, 1H), 7.74 (s, 1H), 7.69 (d, J=9.1 Hz, 2H), 7.31 (d, J=9.1 Hz, 2H), 4.50 (s, 2H). APCI MS m/z 321, 323 [M+H]+.

Provenance & Evidence