Dimethylformamide → Methyl 5-bromo-3-[(2,2-difluoroethyl)amino]thiophene-2-carboxylate

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Reaction Steps

A mixture of methyl 5-bromo-3-[(trifluoroacetyl)amino]thiophene-2-carboxylate (500 mg, 1.51 mmol), 2,2-difluoroethyl trifluoromethanesulfonate (441 mg, 2.06 mmol), cesium carbonate (1.23 g, 3.78 mmol) and DMF (10 mL) was microwave-irradiated at 90° C. for 1 h. Then, water was added to quench the reaction. The organic materials were extracted with EtOAc. The combined extracts were washed with water and brine, dried over Na2SO4 and filtered. After removal of the solvent at reduced pressure, the residue was dissolved in MeOH (3 mL). To the solution were added potassium carbonate (100 mg) and water (1.5 mL). The mixture was stirred at room temperature for 0.5 h. After removal of the solvent at reduced pressure, the organic materials were extracted with EtOAc. The combined extracts were washed with brine, dried over Na2SO4 and filtered. After removal of the solvent at reduced pressure, the residue was purified by column chromatography (Purif, silica gel, hexane to 85:15 hexane/EtOAc) to give the title compound (290 mg, 64%) as a yellow solid:

Provenance & Evidence