反应详情

According to General Procedure A; ethyl benzoylacetate (18.4 mL, 95.5 mmol, 1.1 equ.) in ethanol (180 mL) was treated at 0° C. with methylhydrazine (4.57 mL, 86.8 mmol, 1.0 equ.) to give 1-methyl-3-phenyl-1H-pyrazol-5(4H)-one (11.0 g 63.1 mmol, 73%) after purification by crystallization (ethanol) as a light yellow solid. 1H-NMR (400 MHz) CDCl3: 7.67-7.65 (m, 2H), 7.42-7.41 (m, 3H), 3.60 (s, 2H), 3.41 (s, 3H), 13C-NMR (100 MHz) CDCl3: 171.8, 154.2, 131.0, 130.3, 128.8, 125.6, 37.9, 31.4. LC/MS-MS: 175.0→77.2 m/z; GS1 and GS2 at 30, DP=66, CE=43, CXP=4, tR=3.45 min.