3-Bromothiophene → Methyl 3-bromo-1-(thiophen-3-yl)-1H-indazole-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl 3-bromo-1H-indazole-6-carboxylate (1.801 g, 7.06 mmol), 3-bromothiophene (2.00 mL, 21.35 mmol), trans-1,2-bis(methylamino)cyclohexane (233 μL, 1.478 mmol), copper(I) iodide (142.8 mg, 0.750 mmol), and potassium phosphate tribasic (3.10 g, 14.60 mmol) were dissolved in toluene (35 ml) in a sealed tube and heated to 120° C. The reaction was allowed to stir for 3 h. The reaction was stopped, cooled to room temperature, quenched by addition of saturated aqueous ammonium chloride (25 mL), and the mixture extracted with ethyl acetate (3×30 mL). The combined organic phases were washed with saturated aqueous sodium chloride (1×20 mL), dried (sodium sulfate), filtered, and the solvent evaporated under reduced pressure. The crude product was purified by flash chromatography (RediSep SiO2, 120 g column) on a CombiFlash Rf purification system eluting with ethyl acetate-hexanes (0-35%). The title compound (1.4177 g, 4.20 mmol, 59.5% yield) was recovered as a white solid. LC-MS: [M+1]=337.0.

Provenance & Evidence