Hydrochloric Acid → 1-Benzothiophene-2-carbaldehyde

Participants

Reaction Steps

Butyllithium (54 mL, 134 mmol) is added dropwise to a solution of N,N,N',N'-tetramethylethylenediamine (15.57 g, 134 mmol) in tetrahydrofuran under nitrogen at 0° C. The reaction mixture is treated dropwise with a solution of benzothiophene (15.00 g, 112 mmol) in tetrahydrofuran, warmed to room temperature, treated with additional N,N,N',N'-tetramethylethylenediamine (15.57 g, 134 mmol) and butyllithium (54 mL, 134 mmol), stirred at room temperature for 13 hours, cooled to 0° C., treated with N,N-dimethylformamide (24.40 g, 336 mmol), warmed to room temperature, stirred for five hours, poured into one molar hydrochloric acid and extracted with ether. The combined organic extracts are washed sequentially with water and brine, dried over Na2SO4 and concentrated in vacuo to obtain an orange oil. Flash chromatography of the oil using silica gel and a 15% ethyl acetate in hexane 25 solution gives the title product as an orange oil (12.51 g, 69%).

Provenance & Evidence