2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 1-Phenyl-5-(trifluoromethyl)-1H-pyrazol-3-amine

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Reaction Steps

A mixture of 1-phenyl-5-(trifluoromethyl)-4,5-dihydro-1H-pyrazol-3-amine (1.47 g, 6.41 mmol) and DDQ (1.748 g, 7.7 mmol) in CH2Cl2 (30 mL) was stirred at room temperature for 4 hours. The crude product was purified by silica gel chromatography twice (with 15-35% and 10-30% EtOAc/hexane as eluants) to afford 1-phenyl-5-(trifluoromethyl)-1H-pyrazol-3-amine as an oil (0.666 g, 46%). 1H NMR (300 MHz, CDCl3) δ 7.42 (m, 5H), 6.18 (s, 1H), 3.82 (br, 2H); LC-MS (ESI) m/z 228 (M+H)+.

Provenance & Evidence