The synthesis of 3-iodoindazole was carried out according to the method previously reported by Bocchi [28] with slight modifications. The procedure was as follows: 1H-indazole (3 g, 25.4 mmol), iodine (12.7 g, 50.03 mmol) and potassium hydroxide (5.34 g, 95.25 mmol) were dissolved in DMF (7 mL) and the reaction was stirred for 3 h at room temperature. Upon completion of the reaction, saturated sodium bisulfite solution (150 mL) was added to quench the reaction, at which time a precipitate was generated. The precipitate was collected by vacuum filtration and washed with distilled water (3 x 30 mL). The resulting solid was dried overnight in a vacuum oven at 30 °C to give 6.17 g of light yellow solid product in 100% yield. The product was characterized as follows: melting point 136-138 °C (literature value [36]: 134-136 °C); IR (KBr) ν (cm-1): 3086 (NH), 424 (C-I); 1H-NMR δ (ppm): 13.50 (1H, s, H-1), 7.55 (1H, d, J=8.6 Hz, H-7), 7.45- 7.40 (2H, m, H-6 and H-4), 7.19 (1H, dd, J=7.5 Hz, H-5); 13C-NMR δ (ppm): 140.41, 127.22, 126.79, 121.23, 120.39, 110.51, 93.49; HRMS (calculated value C7H5IN2: 243.9497. measured value: 243.9499).
