Hydrochloric Acid → 1-(3,4-Dichlorophenyl)-1H-pyrazol-3-amine

Participants

Reaction Steps

A solution of sodium ethoxide in ethanol was prepared by dissolving sodium (0.5 g, 21.9 mmol) in ethanol (25 ml) in a dry nitrogen atmosphere and 3,4-dichlorophenylhydrazine hydrochloride (1.85 g, 8 mmol) was added. The mixture was warmed to reflux for 45 min. with stirring, then cooled to room temperature and ethoxyacrylonitrile (1.4 g, 14 mmol) added and warmed again to reflux for 24 hours. The reaction mixture was cooled to room temperature and followed by addition of water (7 ml) and 6N HCl to adjust the pH to ≈2. The resulting aqueous-ethanolic solution was stirred at room temperature for 3 hours, treated with 10% aq. NaOH to a pH 7-8 and stirred overnight. A red colour solid appeared and it was filtered, washed with water and dried to give 1-(3,4-dichlorophenyl)-1H-pyrazol-3-amine (1.57 g, 88% yield)

Provenance & Evidence