4-Fluorophenylhydrazine hydrochloride → HCID 67199165, compound

Participants

Reaction Steps

To a solution of 2-[1-dimethylamino-meth-(Z)-ylidene]-4,4-diethoxy-3-oxo-butyric acid ethyl ester (625 mg, 2.28 mmol) in methanol (10 mL) is added 4-fluorophenylhydrazine hydrochloride (410 mg, 2.5 mmol). The mixture is warmed at reflux. After 2 hours, the reaction mixture is cooled to room temperature, concentrated in vacuo, diluted with water (15 mL) and extracted with ether (3×15 mL). The combined ether layers are washed with brine (2×15 mL), dried over magnesium sulfate, filtered and concentrated. The residue is purified by silica gel chromatography eluting with a gradient of 0-10% EtOAc in hexanes to afford 5-diethoxymethyl-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acid ethyl ester.

Provenance & Evidence