To a solution of ethyl 3-cyclopropyl-3-(3-(((2′-fluoro-5′-methoxy-2-neopentyl-[1,1′-biphenyl]-4-yl)amino)methyl)phenyl)propanoate (92 mg) in DMF (0.89 mL) were added 2,2,2-trifluoroethyl trifluoromethanesulfonate (77 μL) and potassium carbonate (74 mg) at 0° C., and the mixture was stirred at 80° C. for 15 hr. The reaction mixture was cooled to 0° C., potassium carbonate (246 mg) was added, and the mixture was stirred at 80° C. for 2 days. The reaction mixture was cooled to 0° C., 2,2,2-trifluoroethyl trifluoromethanesulfonate (256 μL) was added, and the mixture was further stirred at 80° C. for 3 days. The mixture was cooled to room temperature, poured into water, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure and the residue was directly used for the next reaction.
