Dimethyl Sulfoxide → 5-Fluoro-1-benzofuran-3-carbaldehyde

Participants

Reaction Steps

At a constant temperature of −60° C. dimethylsulfoxide (3.27 g, 41.8 mmol) in dichloromethane (10 mL) was added to a solution of oxalylchloride (2.65 g, 20.9 mmol) in dichloromethane (30 mL) and the solution was stirred for 15 minutes. 1-(5-Fluorobenzofuran-3-yl)methanol (3.16 g, 19.0 mmol) dissolved in dichloromethane (60 mL) was added dropwise at −60° C. The mixture was stirred for 20 minutes followed by addition of triethylamine (9.61 g, 0.095 mmol). After stirring for 10 minutes, the reaction mixture was allowed to heat to ambient temperature and stirred for additional 20 minutes. The organic fraction was washed successively with 50 mL portions of water, 1N aqueous HCl, saturated aqueous sodium bicarbonate and brine, then dried (MgSO4) and concentrated in vacuo to furnish crude title compound in quantitative yield as a beige crystalline solid. 1H NMR (CDCl3): 7.13 (dt, 1H); 7.50 (dd, 1H); 7.86 (dd, 1H); 8.30 (s, 1H); 10.15 (s, 1H).

Provenance & Evidence