To a mixture of 6-((2,4-dichlorobenzyl)oxy)-3-sulfanyl-1-benzothiophene-2-carboxamide (40 mg) in THF (dry) (4.0 mL) were added sodium hydrogen carbonate (13.1 mg) and ethyl 2-bromoacetate (0.017 mL). The mixture was stirred overnight at room temperature. To the mixture was added DMF (1.0 mL) and stirred at room temperature over weekend. The mixture was quenched with water and extracted with EtOAc. The combined organic layer was washed successively with water and brine, dried over MgSO4, and concentrated in vacuo. The residue was purified by silica gel column chromatography (EtOAc/hexane) to give the title compound (25.2 mg).
