Phosphorus tribromide → 4-(Bromomethyl)-5-cyclopropyl-3-[2-(trifluoromethoxy)phenyl]isoxazole

Participants

Reaction Steps

To a solution of (5-cyclopropyl-3-(2-trifluormethoxy-phenyl)-isoxazol-4-yl)-methanol (2.19 g, 7.32 mmol) in anhydrous methylene chloride (50 mL) at 0° C. is added PBr3 (0.83 mL, 8.7 mmol) and the mixture is stirred for 3 hours. The mixture is then poured into 100 mL of ice water and extracted with DCM (2×). The combined DCM layers are washed with brine, dried (MgSO4) and concentrated under reduced pressure to provide crude residue. The residue is purified via flash chromatography (120 g silica) eluting with a gradient of 0 to 60% ethyl acetate in heptane to provide the title compound (2.1 g, 79%) as an oil.

Provenance & Evidence