Hexachloroethane → 1-Ethyl-4-nitro-1H-pyrazole

Temperatur

-78 °C

To a solution of 5-chloro-1-ethyl-4-nitro-1H pyrazole (1 equiv) in THF (0.6 M) was added dropwise a 1.0 M solution of lithium bis(trimethylsilyl)amide (2.6 equiv) at −78° C. The reaction mixture was stirred at −78° C. for 30 min before the addition of hexachloroethane (1.5 equiv) in THF (1.2 M). The mixture was stirred at −78° C. for 2.5 h then warmed to room temperature. The reaction was diluted with brine (1.8 M) 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 silica gel chromatography (10-15% ethyl acetate in petroleum ether) to afford the desired product as a white solid (88.2% yield). MS (ESI) m/z 176.0 [M+H]+.

1. temperaturethen warmed 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 silica gel chromatography (10-15% ethyl acetate in petroleum ether)

ORD-Eintrag

ord-e7948c0b803a4f35829f570a8f958ee2

Quelldatensatz

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09428509B2