Hydrazine hydrate (1:1) → 5-(4-Chloro-phenyl)-2,4-dihydro-pyrazol-3-one

Participants

Reaction Steps

A mixture of 26 g (0.10 mmol) of ethyl α-(4-chlorobenzoyl)isobutyrate, 10 g (0.20 mmol) of hydrazine monohydrate and 200 ml of ethanol was heated under reflux for 18 hours. The reaction solution was concentrated under reduced pressure. The obtained crude product was washed successively with water, methanol-water and diethyl ether-n-hexane, and then air dried to give 16 g of the object compound as white crystals (yield 84%).

Provenance & Evidence