反应详情

温度

40 °C

A stirred solution of NaHMDS in THF (1.0 M, 3.1 mL, 3.1 mmol) was cooled in an ice water bath under Ar. 3-iodo-1H-pyrazole (500 mg, 2.6 mmol) was added as a solution in DMF (1 mL), washing with additional DMF (2×1 mL). tert-butyl 2-bromo-2-methylpropanoate (0.58 mL, 3.1 mmol) was added and the reaction mixture was removed from the cold bath and heated to 40° C. After 16 h, the reaction mixture was cooled and diluted with water and EtOAc. The phases were separated, and the organic phase was washed with water and brine, dried over Na2SO4, filtered and concentrated. The crude residue was purified by silica gel chromatography (0-20% EtOAc in hexanes) to afford tert-butyl 2-(3-iodo-1H-pyrazol-1-yl)-2-methylpropanoate 7.03 (649 mg). 1H NMR (400 MHz, Chloroform-d) δ 7.36 (d, J=2.4 Hz, 1H), 6.42 (d, J=2.4 Hz, 1H), 1.79 (s, 6H), 1.38 (s, 9H).

1. washwashing with additional DMF (2×1 mL)
2. customthe reaction mixture was removed from the cold bath
3. temperaturethe reaction mixture was cooled
4. additiondiluted with water and EtOAc
5. customThe phases were separated
6. washthe organic phase was washed with water and brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude residue was purified by silica gel chromatography (0-20% EtOAc in hexanes)