Potassium Fluoride → methyl 4-[1-methyl-4-(trifluoromethyl)-1H-pyrazol-5-yl]-2-thiophenecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-(4-iodo-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (470 mg, 1.35 mmol), copper (I) iodide (256 mg, 1.35 mmol) and potassium fluoride (78 mg, 1.35 mmol) in anhydrous DMF/HMPA (2 ml/2 mL) was added triethyl(trifluoromethyl)silane (745 mg, 4.04 mmol). The mixture was heated to 70° C. under N2 in a sealed tube. After 10 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, 10-30%) to afford the title compound (0.29 g, 74%) as a yellow syrup: LC-MS (ES) m/z 291 (M+H)+.

Provenance & Evidence