Dimethylformamide → 3-ethyl-N-{2-fluoro-5-[(2-{[(2-methylcyclopropyl)carbonyl]amino}imidazo[1,2-b]pyridazin-6-yl)oxy]phenyl}-1-methyl-1H-pyrazole-5-carboxamide

Participants

Reaction Steps

To a solution of 3-ethyl-1-methyl-1H-pyrazole-5-carboxylic acid (158 mg, 1.03 mmol) in tetrahydrofuran (3.8 mL) were added N,N-dimethylformamide (20 μL, 0.26 mmol) and oxalyl chloride (90 μL, 1.03 mmol), and the mixture was stirred at room temperature for 30 min. The reaction mixture was added to a solution of N-[6-(3-amino-4-fluorophenoxy)imidazo[1,2-b]pyridazin-2-yl]-2-methylcyclopropanecarboxamide (250 mg, 0.73 mmol) in N,N-dimethylacetamide (5.0 mL), and the mixture was stirred at room temperature for 2 hr. Saturated aqueous sodium hydrogencarbonate solution was added to the reaction mixture, and the mixture was extracted with ethyl acetate/tetrahydrofuran, washed with saturated brine, dried over anhydrous sodium sulfate, and filtrated. The solvent was evaporated under reduced pressure, the residue was purified by silica gel column chromatography (ethyl acetate alone) and recrystallized from hexane/ethyl acetate to give the title compound (201 mg, 57%) as a white powder.

Provenance & Evidence