Dimethylformamide → methyl 4-(8-bromo-N-methyl-4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamido)-3-chlorobenzoate

To a solution containing methyl 3-chloro-4-(methylamino)benzoate (0.184 g, 0.922 mmol) in N,N-dimethylformamide (11.0 mL, 142 mmol) was added sodium hydride (0.0369 g, 0.922 mmol). The mixture was stirred at room temperature 30 min then 8-bromo-4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carbonyl chloride (0.288 g, 0.838 mmol) was added. The reaction mixture was stirred for 16 hr. The reaction mixture was quenched with sat. NH4Cl, extracted with DCM (2×). The combined organics were dried (Na2SO4), filtered and concentrated. The crude product was purified by flash chromatography EtOAc/Hex (0-100%) to give methyl 4-(8-bromo-N-methyl-4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamido)-3-chlorobenzoate (yield 65%). MS: (ESI+) 508.2