To a solution of 4-isopropoxy-3-(trifluoromethyl)benzonitrile (183 g, 798 mmol) in ethanol (1 L) was added 5 N sodium hydroxide solution (559 mL, 2.80 mol). The reaction mixture was heated to 80 °C and kept for 18 hours. Upon completion of the reaction, the volatiles were removed by vacuum and 3 N hydrochloric acid was added to the residue until the mixture became acidic. At this point a precipitate was formed and the precipitate was collected by vacuum filtration. The solid was washed with water and hexane. The solid was dissolved in ethyl acetate, dried over magnesium sulfate, filtered and concentrated to give 4-isopropoxy-3-(trifluoromethyl)benzoic acid (191 g, 770 mmol, 96% yield) as a white solid. The calculated value for the exact mass was 248.1, measured value: LCMS m/z = 249.3 [M + H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.41 (d, J = 6.0 Hz, 6H), 4.76 (sep, J = 6.0 Hz, 1H), 7.05 (d, J = 8.8 Hz, 1H), 8.22 (dd, J1 = 8.8 Hz, J2 = 2.2 Hz, 1H), 8.33 (d, J = 2.0 Hz, 1H).
