反应详情

温度

0 °C

A flask was charged with 5-chloro-1H-indazole (4.9 g, 32.11 mmol) and DMF (30 mL). It was then cooled to 0° C., and a solution of bromine (2.4 mL, 46.86 mmol) in DMF (30 mL) was added over several minutes. After addition was complete, the flask was warmed to rt and stirred for 4 hours. Additional bromine (0.89 mL, 16 mmol) was added, and the reaction stirred at room temperature for 20 minutes. The reaction was poured into 600 mL of ice-cold 1% (w/v) Na2S2O3 solution, and the precipitated product was filtered off. The product was redissolved in EtOAc (500 mL), washed with saturated aqueous NaHCO3 then brine, dried over Na2SO4, and concentrated to afford the product. 1H NMR (400 MHz, DMSO-d6) δ 13.60 (br s, 1H), 7.68-7.54 (m, 2H), 7.44 (dd, J=9.0, 1.8 Hz, 1H).

1. additionAfter addition
2. temperaturethe flask was warmed to rt
3. stirringthe reaction stirred at room temperature for 20 minutes
4. filtrationthe precipitated product was filtered off
5. dissolutionThe product was redissolved in EtOAc (500 mL)
6. washwashed with saturated aqueous NaHCO3
7. dry with materialbrine, dried over Na2SO4
8. concentrationconcentrated
9. customto afford the product