Hydrochloric Acid → HCID 68289650, compound

Participants

Reaction Steps

To a solution of the above compound (358 mg, 1.17 mmol) in tetrahydrofuran (4 mL) was added dropwise a solution of 1.67 mol/L n-butyllithium in hexane (0.84 ml, 1.41 mmol) at −78° C. under argon atmosphere. The mixture was stirred at the same temperature for 90 minutes, and then thereto was added a solution of N-fluorobenzene sulfonimide (553 mg, 1.76 mmol) in tetrahydrofuran (6 mL). The reaction solution was slowly warmed to room temperature, and stirred overnight. To the reaction solution was added water, and the mixture was extracted with ethyl acetate twice. The organic layer was combined, washed with water and saturated brine, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:0→19:1) to give an about 1:1 mixture of 3-fluoro-5-[(methoxymethoxy)methyl]-2-(trifluoromethyl)thiophene and 2-[(methoxymethoxy)methyl]-5-(trifluoromethyl)thiophene. The resulting mixture was dissolved in ethanol (2 mL), and then thereto was added 6 mol/L hydrochloric acid solution (1 mL) at room temperature. The mixture was stirred at the same temperature overnight, and then the reaction solution was alkalified by the addition of saturated aqueous sodium hydrogen carbonate solution, and then extracted with ethyl acetate twice. The organic layer was combined, washed with water and saturated brine, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1→3:2) to give the title compound, [4-fluoro-5-(trifluoromethyl)-2-thienyl]methanol (34 mg, 15%) as a colorless and clear oil.

Provenance & Evidence