反应详情

温度

-78 °C

To a solution of 1-(2-methoxyethyl)-4-nitro-1H-pyrazole (1 equiv) in THF (0.5 M) was added dropwise lithium bis(trimethylsilyl)amide (2.7 equiv) in THF (1.0 M) at −78° C. The reaction was stirred at −78° C. for 30 min before the addition of hexachloroethane (1.5 equiv) in THF (1.84 M). The reaction was stirred at −78° C. for 2.5 h before warming to room temperature. The reaction was diluted with brine and extracted with ethyl acetate. The combined extracts were washed with brine, dried over sodium sulfate, filtered and concentrated. The crude product was purified by flash chromatography (10-20% ethyl acetate in petroleum ether) to afford the desired product as a yellow solid (83% yield). 1H NMR (400 MHz, CHLOROFORM-d1) δ ppm 8.13 (s, 1H), 8.08 (s, 1H), 4.31-4.28 (t, J=4.2 Hz, 2H), 3.74-3.72 (t, J=5.36 Hz, 2H), 3.37 (s, 3H).

1. temperaturebefore warming to room temperature
2. extractionextracted with ethyl acetate
3. washThe combined extracts were washed with brine
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude product was purified by flash chromatography (10-20% ethyl acetate in petroleum ether)