Phenylhydrazine → 5-(4-Methoxyphenyl)-2-phenyl-2,4-dihydro-3H-pyrazol-3-one

Participants

Reaction Steps

Using General Procedure A; ethyl-4-methoxybenzoylacetate (7.00 g, 27.8 mmol, 1.1 equ.) in ethanol (100 mL) was treated at 0° C. with phenylhydrazine (2.50 mL, 25.3 mmol, 1.0 equ.) to give 3-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-5(4H)-one (5.21 g, 19.6 mmol, 78%) after crystallization (ethanol) as a light yellow solid. 1H-NMR (400 MHz) CDCl3: 7.99-7.97 (d, 1H), 7.66-7.64 (d, 2H), 7.44-7.40 (t, 2H), 7.22-7.18 (t, 1H), 6.94-6.92 (d, 2H), 3.82 (s, 3H), 3.68 (s, 3H), 13C-NMR (100 MHz) CDCl3: 170.1, 161.5, 154.4, 138.2, 128.8, 127.5, 125.0, 123.5, 118.8, 114.2, 55.3, 39.6; LC/MS-MS: 267.0→77.2 m/z; GS1 and GS2 at 30, DP=81, CE=65, CXP=4, tR=4.15 min.

Provenance & Evidence