Hydrazine hydrate (1:1) → 3-Phenyl-5-pyrazolone

Participants

Reaction Conditions

Reaction Steps

To a solution of propyl 3-oxo-3-phenylpropanoate (10 g, 48.5 mmol) in ethanol (100 mL) was added hydrazine hydrate (9.71 g, 194 mmol) at room temperature. The reaction was heated to 80° C. for 2 h, cooled to room temperature and concentrated. The residue was crystallized from 20% ethyl acetate/hexane to give the title compound (6.58 g). LCMS m/z=161.08 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm, 2.32 (br, 2H), 7.32-7.78 (m, 5H), 12.1 (s, 1H).

Provenance & Evidence