Step 1) Synthesis of 5-methyl-2-(2H-1,2,3-triazol-2-yl)benzoic acid: under nitrogen protection, N,N-dimethylformamide (30 mL), 1,2,3-triazole (3.45 g, 50 mmol), 2-iodo-5-methylbenzoic acid (5.24 g, 20 mmol), caesium carbonate (11.72 g, 36 mmol), trans-N,N'-dimethyl-1,2-cyclohexanediamine (0.51 g, 3.6 mmol) and cuprous iodide (0.38 g, 2 mmol). The reaction mixture was heated to 100 °C for 4 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with water (60 mL) and extracted with ethyl acetate (200 mL x 2). The aqueous layer was acidified to pH 1 to 2 with concentrated hydrochloric acid and extracted again with ethyl acetate (200 mL x 2). The organic layers were combined, dried with anhydrous sodium sulfate and filtered. The filtrate was concentrated under vacuum and the residue was purified by silica gel column chromatography (dichloromethane/methanol, v/v=50/1) to give the title compound as a yellow solid (2.76 g, 68%). Mass spectrum (ESI, negative ion) m/z: 202.1 [M-H]-; 1H NMR (CD3OD, 600 MHz) δ (ppm): 7.88 (s, 2H), 7.66 (d, 1H), 7.59 (d, J=8.2 Hz, 1H), 7.50-7.48 (dd, J=8.1 Hz, 1.1 Hz, 1H), 2.45 ( s, 3H); 13C NMR (CD3OD, 151MHz) δ (ppm): 169.8, 140.7, 137.5, 136.7, 133.5, 131.5, 129.3, 126.0, 21.0.
