Sodium Hydroxide → 5-(4-bromo-2-nitrophenyl)-1-cyclopentyl-1H-pyrazole

Participants

Reaction Steps

Under a nitrogen atmosphere, to a solution of 1.15 g of (2E)-1-(4-bromo-2-nitrophenyl)-3-(dimethylamino)prop-2-en-1-one in 9.2 mL of acetic acid was added 1.05 g of cyclopentylhydrazine hydrochloride, followed by stirring at room temperature for 60 hours. The reaction mixture was poured into a mixture of water/ethyl acetate, followed by adjusting to pH 10 with a 6 M aqueous sodium hydroxide solution. The aqueous layer was separated, and then the organic layer was washed with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and then the residue was purified by silica gel column chromatography (n-hexane/ethyl acetate) to obtain 940 mg of 5-(4-bromo-2-nitrophenyl)-1-cyclopentyl-1H-pyrazole.

Provenance & Evidence