N-[5-(3,5-Difluoro-benzyloxy)-1H-indazol-3-yl]-4-[(3-dimethylamino-propyl)-methyl-amino]-2-nitro-benzamide (424 mg, 0.79 mmol) in DCM (5 mL) was treated with nBu4NCl (149 mg, 0.54 mmol). Na2S2O4 (969 mg, 4.73 mmol) in water (5 mL) was added drop-wise, with stirring. After 1 hour, the volatiles were removed by evaporation, the residue was taken twice in water, filtered and treated with 4N HCl in dioxane (12 mL). The volatile components were removed by evaporation. The solid was dissolved in DCM (100 mL), washed with saturated NaHCO3 solution and brine. After drying over sodium sulfate and removal of the solvent, the crude was purified over silica gel (DCM: NH3 7N in MeOH 9:1) to afford 260 mg of title compound in 65% yield.
