Into a 50-mL round-bottom flask, was placed ethyl 3-(4-[[3-(4-chlorophenyl)-5-(trifluoromethyl)-1,2-thiazol-4-yl]methoxy]-2,3-difluorophenyl)propanoate (101 mg, 0.20 mmol, 1.00 equiv), tetrahydrofuran (2.0 mL), a solution of LiOH (100 mg, 4.18 mmol, 20.91 equiv) in water (2.0 mL). The resulting solution was stirred overnight at 30° C. The reaction progress was monitored by LCMS. The pH value of the solution was adjusted to 1 with aqueous HCl (2 N). The resulting mixture was concentrated under vacuum. The solids were collected by filtration and washed by hexane and EtOAc. Then the solid was dried under vacuum. This resulted in 85 mg (89%) of 3-(4-[[3-(4-chlorophenyl)-5-(trifluoromethyl)-1,2-thiazol-4-yl]methoxy]-2,3-difluorophenyl)propanoic acid as a white solid. 1H-NMR (300 MHz, CD3OD) δ 7.69 (d, J=8.4 Hz, 2H), 7.51 (d, J=8.4 Hz, 2H), 7.01 (t, J=7.5 Hz, 1H), 6.85 (t, J=7.5 Hz, 1H), 5.19 (s, 2H), 2.94 (t, J=7.8 Hz, 2H), 2.61 (t, J=7.8 Hz, 2H). Mass spectrum (ESI, m/z): Calcd. for C20H13ClF5NO3S, 478.0 (M+H). found 478.1.
