Into a 25-mL round-bottom flask, was placed ethyl 3-(3,5-difluoro-4-[[3-(6-methoxypyridin-3-yl)-5-(trifluoromethyl)-1,2-thiazol-4-yl]methoxy]phenyl)propanoate (prepared according to the procedure following Example 1 step 1-5 using 6-methoxynicotinamide as starting material) (50 mg, 0.10 mmol, 1.00 equiv), tetrahydrofuran (1 mL), LiOH (50 mg, 2.09 mmol, 20.98 equiv), water (1 mL). The resulting solution was stirred overnight at 20° C. The resulting mixture was concentrated under vacuum. The pH value of the solution was adjusted to 6 with hydrogen chloride (2 mol/L). The solids were collected by filtration. The crude product (20 mg) was purified by Flash-Prep-HPLC with the following conditions (IntelFlash-1): Reversed Column, C18 silica gel; mobile phase, 0.05% TFA/ACN=1/4 increasing to 0.05% TFA/ACN=0/1 within 20 min; Detector, UV 254 nm. This resulted in 8.8 mg (18%) of 3-(3,5-difluoro-4-((3-(6-methoxypyridin-3-yl)-5-(trifluoromethyl)isothiazol-4-yl)methoxy)phenyl)propanoic acid as a white solid. 1H NMR (300 MHz, CD3OD) δ 8.51 (s, 1H), 8.06 (d, J=6.3 Hz, 1H), 6.80-6.89 (m, 3H), 5.19 (s, 2H), 3.96 (s, 3H), 2.83 (t, J=7.5 Hz, 2H), 2.56 (t, J=7.5 Hz, 2H). Mass spectrum (ESI, m/z): Calcd. for C20H15F5N2O4S, 475.1 (M+H). found 475.1.
