Acetic Acid → 1-(2-Fluoro-5-iodophenyl)-5-methoxy-3-(1-phenyl-1H-pyrazol-5-yl)pyridazin-4(1H)-one

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Reaction Steps

A mixture of 3-acetyl-1-(2-fluoro-5-iodophenyl)-5-methoxypyridazin-4(1H)-one (3.88 g, 10.0 mmol) in N,N-dimethylformamide dimethyl acetal (38.8 mL) was heated to reflux for 3 h. The mixture was concentrated in vacuo. To the residue were added AcOH (38.8 mL) and phenylhydrazine (1.97 mL, 20.0 mmol). The mixture was heated to reflux for 5 h. The mixture was concentrated in vacuo, diluted with 1 M HCl aqueous solution, extracted with AcOEt, washed with saturated NaHCO3 aqueous solution, dried over Na2SO4, filtered, concentrated in vacuo, purified by column chromatography on basic silica gel (hexane/AcOEt=50/50 to 0/100) and triturated with AcOEt/hexane to yield the title compound (2.95 g, 60% yield) as a yellow solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.77 (3H, s), 6.99 (1H, d, J=1.5 Hz), 7.23-7.50 (7H, m), 7.79 (1H, d, J=1.9 Hz), 7.84 (1H, ddd, J=8.7, 4.5, 2.3 Hz), 8.49 (1H, d, J=2.6 Hz).

Provenance & Evidence