Ethanol → 2-(2-fluorophenyl)-5-{[4-(1H-pyrazol-1-yl)phenyl]methyl}-2,5-dihydro-3H-pyrazolo[4,3-c]cinnolin-3-one

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Reaction Steps

Ethyl 1-{[4-(1H-pyrazol-1-yl)phenyl]methyl}-4-thioxo-1,4-dihydrocinnoline-3-carboxylate (160 mg, 0.410 mmol) was dissolved in 1,2-dimethoxyethane (2 mL) and absolute ethanol (1 mL). 2-Fluorophenylhydrazine (114 mg, 0.902 mmol, 2.2 equiv) and potassium carbonate (170 mg, 1.23 mmol, 3.0 equiv) were added. The mixture was stirred vigorously for 15 minutes at ambient temperature and then placed into an oil bath preheated to 98° C. for 7 hours. The mixture was cooled ambient temperature, diluted with chloroform and washed once with water. The aqueous layer was extracted once with chloroform and the combined organic extracts were dried with sodium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel gradient chromatography (100:0 to 99:1; chloroform:methanol), providing the titled compound: 1H-NMR (400 MHz, CDCl3) δ 8.32 (1H, d, J=7.8 Hz), 7.90 (1H, s), 7.71-7.61 (4H, m), 7.60-7.52 (3H, m), 7.43-7.37 (3H, m), 7.31-7.26 (2H, m), 6.47 (1H, s), 5.88 (2H, s) ppm; high resolution mass spectrometry (ES+) m/z 437.1517 [(M+H)+; calculated for C25H18FN6O: 437.1521].

Provenance & Evidence