Boron trifluoride → HCID 71269853, compound

Participants

Reaction Steps

A solution of 3-{1-ethyl-4,4-difluoro-5-hydroxy-3-[4-(trifluoromethyl)phenoxy]-4,5-dihydro-1H-pyrazol-5-yl}benzonitrile (crude, 2.1 g, 5.11 mmol), DCM (25.5 mL) and triethylsilane (2.45 mL, 15.3 mmol) was cooled to −78° C. and treated with BF3 etherate (1.94 mL, 15.3 mmol) in a single portion. The reaction was allowed to warm to rt overnight and checked via LCMS at 16 h. The reaction was treated with DBU (3.85 mL, 25.6 mmol) dropwise and checked via LCMS after 30 minutes, requisite product dominates. The reaction was diluted with EtOAc and washed with sat aq. NaHCO3 2×, brine, dried (MgSO4) and concentrated to afford an opaque brown residue purified via MPLC, 100 g silica, 5-35% EtOAc in heptanes to afford 3-{1-ethyl-4-fluoro-3-[4-(trifluoromethyl)phenoxy]-1H-pyrazol-5-yl}benzonitrile as a clear, colorless oil. MS: cal'd 376 (MH+), exp 376 (MH+).

Provenance & Evidence