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

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).

1. additionwas added dropwise at −60° C
2. stirringThe mixture was stirred for 20 minutes
3. stirringAfter stirring for 10 minutes
4. stirringstirred for additional 20 minutes
5. washThe organic fraction was washed successively with 50 mL portions of water, 1N aqueous HCl, saturated aqueous sodium bicarbonate and brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo

ORD record

ord-465d0ac39a5c4431bde490f719f59cf0

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07368472B2