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

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Reaction Steps

mixture of 3-acetyl-1-[2-fluoro-3-(1-methyl-1H-pyrazol-4-yl)phenyl]-5-methoxypyridazin-4(1H)-one (243 mg, 0.708 mmol) in N,N-dimethylformamide dimethyl acetal (2.4 mL) was heated to reflux for 2 h. The mixture was concentrated in vacuo. To the residue were added AcOH (2.4 mL) and phenylhydrazine (0.139 mL, 1.42 mmol). The mixture was heated to reflux for 2 h. The mixture was 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=20/80 to 0/100) and recrystallized with EtOH/AcOEt/hexane to yield the title compound (193 mg, 62% yield) as a pale yellow solid: mp 218-221° C. 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.78 (3H, s), 3.91 (3H, s), 6.97 (2H, d, J=1.9 Hz), 7.13-7.50 (6H, m), 7.72-7.84 (2H, m), 7.93 (1H, s), 8.18 (1H, d, J=2.3 Hz), 8.55 (1H, d, J=1.9 Hz).

Provenance & Evidence