BOP chloride (0.079 g, 0.309 mmol) was added to a solution of 5-amino-N-({4-chloro-3-[(3-chloro-5-cyanophenyl)oxy]-2-fluorophenyl}methyl)-1H-indole-2-carboxamide trifluoroacetate (0.060 g, 0.103 mmol), 3-[(1,1-dimethylethyl)oxy]propanoic acid (0.015 mL, 0.103 mmol) and diisopropylethylamine (0.090 mL, 0.514 mmol) in DMF (1 mL). The mixture was stirred at room temperature for 2 hr. The reaction mixture was extracted with ethyl acetate and water. The organic layer was washed with water, dried over sodium sulfate and concentrated. The residue was purified by flash chromatography (hexane:ethyl acetate) to give the title compound (0.041 g, 67%) as a white solid. ES MS: m/z 597 (M+1).
