反应详情

To a stirred suspension of 4,4,4-trifluoro-3-oxobutanenitrile (20 g, 145.98 mmol, 1.0 eq.) in ethanol (200 mL) was added (2,3-dichlorophenyl)hydrazine (47.5 g, 145.98 mmol, 1.0 eq) and refluxed for 3 h. Ethanol was evaporated, the residue diluted with water and extracted with ethyl acetate (300 mL×2), dried (Na2SO4), and the solvent evaporated under vacuum. The crude product was purified by CC using EtOAc/PE (3:7) as eluent to get 1-(2,3-dichlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-5-amine (17.02 g, 39.65%, yellow solid; TLC system: EtOAc/PE (1:1) Rf: 0.6).

1. temperaturerefluxed for 3 h
2. customEthanol was evaporated
3. additionthe residue diluted with water
4. extractionextracted with ethyl acetate (300 mL×2)
5. dry with materialdried (Na2SO4)
6. customthe solvent evaporated under vacuum
7. customThe crude product was purified by CC