Methyl 3-(prop-1-en-2-yl)-1-(thiophen-3-yl)-1H-indazole-6-carboxylate (1.0763 g, 3.61 mmol) was dissolved in dimethoxyethane (90 ml)/MeOH (90 ml) at 25° C. Cobalt(II) meso-tetraphenylporphine (25.6 mg, 0.038 mmol) and tetraethylammonium borohydride (1.316 g, 9.07 mmol) were added sequentially. The reaction mixture was allowed to stir for 1.25 h. The reaction was stopped, quenched by addition of saturated aqueous ammonium chloride (100 mL), and the mixture extracted with ethyl acetate (3×80 mL). The combined organic phases were washed with saturated aqueous sodium chloride (1×80 mL), dried (sodium sulfate), filtered, and the solvent evaporated under reduced pressure. The crude product was purified by flash chromatography (RediSep SiO2, 330 g column) on a CombiFlash Rf purification system eluting with ethyl acetate-hexanes (0-45%). The title compound (912.2 mg, 2.88 mmol, 80% yield) was recovered as an orange solid. LC-MS: [M+1]=317.1.
