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

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).

1. temperatureat reflux
2. concentrationThis reaction solution was concentrated under reduced pressure
3. additionwater was added
4. extractionthe mixture was extracted with ethyl acetate
5. washThis organic layer was sequentially washed with water
6. concentrationa saturated aqueous solution of sodium chloride, and then concentrated under reduced pressure
7. customThe resulting residue was purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=2/1 to 1/1)

ORD record

ord-afc7bcc94e5c4b498feaeb05f2571b71

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08846746B2