Potassium Fluoride → Methyl 4-bromo-5-(trifluoromethyl)thiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-bromo-5-iodo-2-thiophenecarboxylate (500 mg, 1.44 mmol), copper (I) iodide (137 mg, 0.72 mmol) and potassium fluoride (251 mg, 4.32 mmol) in DMF/HMPA (5 ml/5 mL) was added methyl difluoro(fluorosulfonyl)acetate (1.1 g, 5.76 mmol). The mixture was heated at 70° C. under N2 in a sealed tube. After 1 h, the reaction was quenched with NH4Cl (sat'd) (2 mL), extracted with ether (5 mL×5) and washed with distilled water (5 mL×5). The combined organic phase was dried over Mg2SO4 and purified on silica (EtOAc/Hex, 20-50%) to afford the title compound (0.82 g) containing a 60% inseparable impurity: LC-MS m/z (ES) 290 (M+H)+.

Provenance & Evidence