Ethyl 3-(2-fluorophenyl)-3-oxopropanoate → 2,5-bis(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one

Participants

Reaction Conditions

Reaction Steps

Ethyl 3-(2-fluorophenyl)-3-oxopropanoate (2.5 g, 12 mmol) and 2-fluorophenyl hydrazine hydrochloride (1.5 g, 12 mmol, 1.0 equiv) were dissolved in acetic acid (24 mL) and placed into a preheated oil bath at 120° C. for 3 hours and then heated for an additional 2 hours at 135° C. The mixture was cooled to ambient temperature, concentrated in vacuo and then concentrated once from toluene (1×25 mL). The residue was suspended in dichloromethane, filtered and the solid was washed once with dichloromethane and dried in vacuo, providing the titled compound. The resulting filtrate was concentrated in vacuo and purified by silica gel gradient chromatography (100:0 to 65:35; hexanes:ethyl acetate), providing additional titled compound as a light brown solid.

Provenance & Evidence