Trifluoroacetic acid → 4-[(5S)-5-(3,5-dichloro-4-fluoro-phenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methyl-benzoic acid

Participants

Reaction Conditions

Reaction Steps

A 100 mL vessel was charged with tert-butyl 4-[(5S)-5-(3,5-dichloro-4-fluoro-phenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methyl-benzoate (3.1 g, 6.3 mmol) and dissolved in CH2Cl2 (30 mL) and then cooled down to 0° C. To this mixture 2,2,2-trifluoroacetic acid (4.3 g, 38 mmol) was added over 10 min. After addition the reaction was brought to room temperature and the mixture stirred over night after which time LC-MS analysis showed a complete conversion. The crude mixture was concentrated and the residue dissolved in 300 mL of ethylacetate, washed with brine, dried over MgSO4 and evaporated to yield 2.7 g of the crude title product which was directly used for the step D.

Provenance & Evidence