反应详情

To a solution of 4-bromo-1-methyl-1H-pyrazol-5-amine (500 mg, 2.84 mmol) and pyridine (0.270 ml, 3.41 mmol) in tetrahydrofuran (9.5 ml) was added 2,2,2-trichloroethyl chloroformate (0.472 ml, 3.41 mmol) with ice-cooling, and the mixture was stirred at room temperature for 2 hours. Water was poured into the reaction solution, and the mixture was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:1) to give 289 mg (28.9%) of the desired product as an oil.

1. temperaturecooling
2. extractionthe mixture was extracted with ethyl acetate
3. washThe extract was washed with water
4. dry with materialdried over anhydrous magnesium sulfate
5. distillationthe solvent was distilled off under reduced pressure
6. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:1)