Trimethylamine oxide → 5-Formylbenzofuran-2-carbonitrile

Participants

Reaction Conditions

Reaction Steps

Trimethlamine-N-oxide (6.75 g, 90 mmol) was added to a solution of 5-(bromomethyl)benzofuran-2-carbonitrile (4.46 g, 18.89 mmol) in 57 mL of DMSO and 6 mL of H2O. The mixture was stirred at 70° C. for 3 hr. After the reaction was cooled to room temperature, the mixture was diluted with 72 mL of brine, and extracted with EtOAc (3×100 mL). The combined organic layers were washed with H2O (2×20 mL), brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The resulting residue was purified by silica gel flash chromatography, 100% Heptane-30% Ethyl Acetate/70% Heptane, to give 5-formylbenzofuran-2-carbonitrile (1.5 g). 1H NMR (400 MHz, DMSO-d6) δ 7.96 (d, J=8.7 Hz, 1H), 8.12 (dd, J=8.7, 1.7 Hz, 1H), 8.30 (d, J=0.9 Hz, 1H), 8.46 (dd, J=1.6, 0.6 Hz, 1H), 10.11 (s, 1H).

Provenance & Evidence