Iodine → 7-ethyl-3-iodo-1H-indazole

Participants

Reaction Steps

To a stirred solution of sodium bicarbonate (1.67 g, 19.8 mmol) in water (4.65 mL) and ethanol (9.3 mL) was added 7-ethyl-1H-indazole (771 mg, 5.27 mmol) followed by iodine (1.87 g, 7.38 mmol). After 16 h the reaction mixture was quenched with sodium thiosulfate, diluted with ethyl acetate and washed with water. The organic layer was collected and dried (MgSO4). Purification by chromatography (silica, 5-25% ethyl acetate/hexanes) gave 7-ethyl-3-iodo-1H-indazole (690 mg, 2.54 mmol, 48%) as an off-white solid. MS (M+H)+=272.9; 1H NMR (CDCl3) δ: 7.39 (d, J=8.1 Hz, 1H), 7.30 (d, J=7.1 Hz, 1H), 7.22 (t, J=7.1 Hz, 1H), 2.95 (q, J=7.5 Hz, 2H), 1.41 (t, J=7.5 Hz, 3H).

Provenance & Evidence