4-Fluorophenylhydrazine hydrochloride → 1-(4-Fluorophenyl)-5-(3-(trifluoromethoxy)phenyl)-4,5-dihydro-1H-pyrazol-3-ylamine

Participants

Reaction Steps

To a solution of a mixture of (E)-3-(3-(trifluoromethoxy)phenyl)acrylonitrile and (Z)-3-(3-(trifluoromethoxy)phenyl)acrylonitrile (1.28 g) in ethanol (13 ml) were sequentially added 4-fluorophenylhydrazine hydrochloride (979 mg) and sodium ethoxide (20 wt % in ethanol, 5.0 ml), and the mixture was stirred overnight at reflux. This reaction solution was concentrated under reduced pressure, and then water was added thereto, and the mixture was extracted with ethyl acetate. This organic layer was sequentially washed with water and a saturated aqueous solution of sodium chloride, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=2/1 to 1/1) to give the titled compound (1.29 g).

Provenance & Evidence