反应详情

3-(2-thienyl)-1H-pyrazole (2.9 mmol) was dissolved in 8 mL N,N-dimethylformamide under argon atmosphere. N-Iodosuccinimide (3.1 mmol) was added in small portions. The reaction mixture was stirred at room temperature overnight. 5% aqueous sodium thiosulfate solution and saturated aqueous sodium carbonate solution were added and the mixture was stirred at room temperature for 1 h. The white precipitate was filtered, washed with little cold MTBE and dried in vacuum to afford 540 mg of 4-iodo-3-(2-thienyl)-1H-pyrazole (66% yield). The filtrate was extracted with ethyl acetate. The combined organic layers were successively washed with water and brine, dried over MgSO4, filtered and concentrated to afford 303 mg of 4-iodo-3-(2-thienyl)-1H-pyrazole (34% yield) that was used without further purification.

1. stirringthe mixture was stirred at room temperature for 1 h
2. filtrationThe white precipitate was filtered
3. washwashed with little cold MTBE
4. customdried in vacuum