Pyrazole → Balipodect

Participants

Reaction Steps

A suspension of 1-(2-fluoro-4-iodophenyl)-5-methoxy-3-(1-phenyl-1H-pyrazol-5-yl)pyridazin-4(1H)-one (4.88 g, 10 mmol), pyrazole (0.681 g, 10 mmol), Cu2O (0.143 g, 1 mmol), salicylaldoxime (0.549 g, 4 mmol), and Cs2CO3 (6.52 g, 20 mmol) in CH3CN (100 mL) was refluxed for 5 h under Ar atmosphere. After cooling to room temperature, the reaction mixture was poured into water and extracted with AcOEt. The extract was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography eluting with hexane/THF (1/2) and recrystallized from EtOH/H2O to give the title compound (1.90 g, 44% yield) as a pale yellow powder: mp 214-216° C.; 1H NMR (300 MHz, CDCl3) δ ppm 3.92 (3H, s), 6.44 (1H, t, J=9.0 Hz), 6.53 (1H, dd, J=1.9, 2.3 Hz), 7.30 (1H, ddd, J=1.1, 2.3, 9.0 Hz), 7.34 (1H, d, J=1.9 Hz), 7.37-7.48 (5H, m), 7.61 (1H, dd, J=2.3, 12.4 Hz), 7.76 (1H, d, J=1.9 Hz), 7.79 (1H, d, J=1.9 Hz), 7.82 (1H, d, J=2.3 Hz), 7.92 (1H, d, J=2.3 Hz). LC-MS (ESI) m/z 429 [M+H]+. Anal. Calcd for C23H17FN6O2: C, 64.48; H, 4.00; N, 19.62. Found: C, 64.41; H, 4.00; N, 19.54.

Provenance & Evidence