反应详情

A mixture consisting of benzaldehyde (290 μL, 2.87 mmol, 1.0 equ.), malononitrile (190 mg, 2.87 mmol, 1.0 equ.) and triethylamine (400 μL, 2.87 mmol, 1.0 equ.) in ethanol (10 mL) was stirred for 1 min, followed by the addition of 1-methyl-3-phenyl-1H-pyrazol-5(4H)-one (500 mg, 2.87 mmol, 1 equ.). The reaction mixture was concentrated after 21 h and washed with ethanol and hexanes; re-crystallized from ethanol, and washed with hexanes and ethanol to give 6-amino-1-methyl-3,4-diphenyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile (282 mg, 8.58 mmol, 30%) as a white solid. 1H-NMR (400 MHz) DMSO: 7.41-7.38 (m, 2H), 7.28-7.24 (m, 2H), 7.21-7.18 (m, 6H), 4.88 (s, 1H), 4.77 (s, 2 H), 3.83 (s, 3H), 13C-NMR (100 MHz) DMSO: 158.1, 146.0, 144.8, 144.6, 133.2, 128.7, 128.5, 127.9, 127.8, 127.1, 126.4, 120.5, 95.7, 59.9, 38.2, 34.5; LC/MS-MS: 329.1→263.1 m/z; GS1 and GS2 at 30, DP=71, CE=31, CXP=18, tR=4.00 min.

1. concentrationThe reaction mixture was concentrated after 21 h
2. washwashed with ethanol and hexanes
3. customre-crystallized from ethanol
4. washwashed with hexanes and ethanol