Sodium Hydroxide → 3-(1-methyl-1H-pyrazol-4-yl)-5-(trifluoromethyl)benzoic acid

Participants

Reaction Steps

To a solution of methyl 3-(1-methyl-1H-pyrazol-4-yl)-5-(trifluoromethyl)benzoate (Int-5, 22.3 g, 78.5 mmol) in methanol (375 mL), was added 1 N NaOH solution (314 mL, 314 mmol). The reaction was stirred at room temperature for 2 h. The methanol was removed by concentration under reduced pressure and the resulting aqueous mixture was acidified to pH 2 with 1 N HCl. The product was isolated by suction filtration, washed with water and hexane and dried under vacuum to provide 3-(1-methyl-1H-pyrazol-4-yl)-5-(trifluoromethyl)benzoic acid as a white solid (Int-6, 20.3 g, 95.7%). LC-MS: (FA) ES+ 271, ES-269; 1H NMR (400 MHz, d6-DMSO) δ ppm 13.53 (s, 1H), 8.44 (s, 1H), 8.33 (s, 1H), 8.16 (s, 1H), 8.09 (d, J=0.7 Hz, 1H), 7.95 (s, 1H), 3.87 (s, 3H).

Provenance & Evidence