Salicylaldehyde oxime → 3-(1-Thiophen-2-yl-1H-pyrazol-5-yl)-1-[3-(trifluoromethyl)phenyl]pyridazin-4(1H)-one

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Reaction Conditions

Reaction Steps

To a mixture of copper (I) oxide (0.028 g, 0.20 mmol), salicylaldoxime (0.11 g, 0.78 mmol), Cs2CO3 (0.64 g, 2.0 mmol) and 3-(1H-pyrazol-5-yl)-1-[3-(trifluoromethyl)phenyl]pyridazin-4(1H)-one (0.30 g, 0.98 mmol) in MeCN (8 mL) was added 2-iodothiophene (0.16 mL, 1.5 mmol), and the mixture was stirred at 90° C. for 1 day. The mixture was diluted with AcOEt and water, and filtered. The filtrate was partitioned between AcOEt and water. The organic layer was washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure. The residue was chromatographed on silica gel (20/80-100/0 AcOEt/hexane) to give yellow crystals. The crystals were purified by preparative HPLC and recrystallized from AcOEt/hexane to give the title compound (11 mg, 3% yield) as off-white crystals: 1H NMR (300 MHz, CDCl3): δ ppm 6.75 (1H, d, J=7.9 Hz), 6.95 (1H, dd, J=5.5, 3.8 Hz), 7.01 (1H, dd, J=3.8, 1.3 Hz), 7.23 (1H, dd, J=5.5, 1.3 Hz), 7.31 (1H, d, J=8.7 Hz), 7.40 (1H, brs), 7.42 (1H, d, J=1.9 Hz), 7.51-7.57 (1H, m), 7.62 (1H, d, J=7.9 Hz), 7.81 (1H, d, J=1.9 Hz), 8.21 (1H, d, J=7.9 Hz). LC-MS (ESI) m/z 389 [M+H]+.

Provenance & Evidence