To a mixture of 2-bromo-4-fluorobenzoic acid (30 g, 137 mmol), cesium carbonate (89.26 g, 274 mmol), and cuprous iodide (5.27 g, 27.4 mmol) in N,N-dimethylformamide (200 mL) was added N,N'-dimethylcyclohexane-1,2-diamine (3.7 mL, 23.3 mmol) and 1H-1 ,2,3-triazole (18.92 g, 274 mmol). The reaction mixture was stirred at 110 °C overnight, cooled, concentrated under reduced pressure and diluted with deionized water (150 mL). The mixture diluted with water was extracted with ethyl acetate (300 mL × 3). The aqueous layer was acidified with 2N hydrochloric acid and extracted again with ethyl acetate (300 mL × 4). All organic layers were combined, washed with saturated saline (150 mL × 3), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate = 100:1 to 5:1) to afford 4-fluoro-2-(2H-1,2,3-triazol-2-yl)benzoic acid (18.13 g) as a yellow solid. Low resolution mass spectrometry (LRMS) showed m/z (M + H)+ of 208.0, which is consistent with the theoretical value of 208.0.
