tert-Butanol → Tert-butyl [6-(3-{[3-(trifluoromethyl)benzoyl]amino}phenoxy)imidazo[1,2-b]pyridazin-2-yl]carbamate

Participants

Reaction Steps

A suspension of 6-(3-{[3-(trifluoromethyl)benzoyl]amino}phenoxy)imidazo[1,2-b]pyridazine-2-carboxylic acid (111 mg, 0.25 mmol), diphenylphosphoryl azide (103 mg, 0.375 mmol), triethylamine (51 mg, 0.5 mmol) and tert-butanol (5.0 mL) was stirred at room temperature for 5 min, heated to 100° C. and stirred overnight. After allowing the reaction mixture to cool to room temperature, ethyl acetate was added to the mixture, and the mixture was washed with saturated aqueous sodium hydrogencarbonate solution, dried over anhydrous magnesium sulfate, and filtrated. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=1/19→ethyl acetate alone) to give the title compound (79 mg, 39%) as a white solid.

Provenance & Evidence