反应详情

A vigorously stirred solution of ethyl benzoylacetate (30 g 150 mmol), of 5% aqueous sodium hydroxide (312 mL), and hydrazine hydrate (14.6 mL 468 mmol) was heated to 75° C. for sixteen hours. The resultant precipitate was filtered, washed with water and dried and gave 5-Phenyl-1,2-dihydro-pyrazol-3-one (20.3) in 81% yield as a white solid. C9H8N2O: 1H NMR (d6-DMSO): δ 7.62 (d, 2H, J=7.0 Hz), 7.36 (t, 2H, J=7.0 Hz), 7.26 (t, 1H, J=7.0 Hz), 5.85 (s, 1H) ppm.

1. filtrationThe resultant precipitate was filtered
2. washwashed with water
3. customdried