Phosphorus oxychloride → 3-Chlorobenzofuran-2-carboxaldehyde

Participants

Reaction Steps

To a cooled solution of phosphorus oxychloride (19 mL, 209 mmol) in DMF (40 mL) is slowly added 2-carboxymethoxybenzoic acid (6.84 g, 35 mmol) in portions. The mixture is warmed to room temperature for 30 min and then heated to 90° C. overnight. The mixture is cooled to room temperature and poured carefully into ice water, extracted with ethyl acetate (3×50 mL), dried with sodium sulfate and concentrated in vacuo. Purification by column chromatography (silica, hexanes/ethyl acetate, 4:1) gave title compound (1.62 g, 26%) as an orange solid. 1H NMR (400 MHz, DMSO-d6) δ 9.98 (s, 1H), 7.82-7.88 (m, 2H), 7.69-7.73 (m, 1H), 5.51-7.56 (m, 1H).

Provenance & Evidence