To a solution of 2-((4-(2-fluoro-4-nitrophenoxy)quinolin-7-yl)oxy)-2-methylpropan-1-ol (5.8 g, 15.6 mmol) in THF (23 mL) was added a solution of HCOOK (9.16 g, 10.9 mmol) in water (7.8 mL), followed by a catalytic amount of Pd/C (5%, 53%˜55% water content). The mixture was heated to 45° C. and stirred for 12 hours, and then filtered through a celite pad. The organic phase was separated, dried over Na2SO4 and concentrated in vacuo to afford a yellow foam solid. The title compound was purified by a silica gel chromatography (EtOAc/DCM=1/1) to give a light yellow solid (4.0 g, 75%).
