Potassium trifluoroacetate → Ethyl 5-trifluoromethyl-6-methoxybenzo[b]thiophene-3-carboxylate

Participants

Reaction Steps

Ethyl-5-bromo-6-methoxybenzo[b]thiophene-3-carboxylate (D4) (0.81 g, 3 mmoles) in dry dimethylformamide (20 ml) and toluene (10 ml) was treated with potassium trifluoroacetate (0.78 g, 6 mmoles) and copper (I) iodide (0.98 g, 6 mmoles). The mixture was heated under reflux for 1 hr using a Dean-Stark trap to collect the toluene. The mixture was cooled and poured into water (150 ml) and extracted with diethyl ether. The resulting emulsion was filtered through kieselguhr. The combined organic extracts were washed several times with water then dried (Na2SO4). Flash chromatography on TLC silica gel eluting with dichloromethane/60-80 petrol ether 1:1 gave the title compound (D6) (0.5 g, 64%)

Provenance & Evidence