反应详情

To a solution of 3-bromo-1H-pyrazole obtained in Step C (1.20 g) in N,N-dimethylformamide (82 mL) was added potassium tert-butoxide tetrahydrofuran solution (1 M, 12.3 mL) at room temperature. The reaction mixture was stirred at room temperature for 10 min, 1,3,2-dioxathiolane 2,2-dioxide (1.52 g) was added thereto at room temperature, and the mixture was stirred for 1 hr. conc. Hydrochloric acid (7.5 mL) was added thereto at room temperature, and the reaction mixture was stirred at room temperature for 18 hr. To the reaction mixture was added ethyl acetate, and the mixture was neutralized with saturated aqueous sodium hydrogen carbonate solution, and washed with saturated brine. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (880 mg).

1. stirringat room temperature, and the mixture was stirred for 1 hr
2. stirringat room temperature, and the reaction mixture was stirred at room temperature for 18 hr
3. washwashed with saturated brine
4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
5. customthe solvent was evaporated under reduced pressure
6. customThe residue was purified by silica gel column chromatography (ethyl acetate/hexane)