4-Bromo-2-ethyl-6-methylaniline → 5-bromo-7-ethyl-1H-indazole

참여 물질

반응 단계

A solution of 4-bromo-2-ethyl-6-methylbenzenamine (3.21 g, 15 mmol) in acetic acid (50 mL) was stirred for 3 hours before addition of a 2 M solution of sodium nitrite (11 mL, 22.5 mmol). The resulting mixture was stirred overnight at room temperature. The solution was concentrated and the solid was dissolved in EtOAc and washed with saturated aqueous NaCl (3×). The organic extract was dried over Na2SO4, filtered and concentrated. the crude material was purified by Biotage chromatography (40M, 15-30% EtOAc/heptane) to provide 5-bromo-7-ethyl-1H-indazole (1.11 g, 33%) and 5-bromo-3,7-dimethyl-1H-indazole (0.84 g, 25%).

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