Hydrochloric Acid → 6-Nitro-1-benzofuran-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

5.8 g (34.7 mmol) of 2-hydroxy-4-nitrobenzaldehyde, 1.28 g (3.5 mmol) of tetrabutylammonium iodide and 19.2 g (138.8 mmol) of potassium carbonate are mixed, 7.9 g (72.9 mmol) of methyl chloroacetate are added, and the mixture is heated at 130° C. for 12 h. 100 ml of THF are added and, while cooling in ice, 11.7 g (208.2 mmol) of potassium hydroxide are added. Addition of 100 ml of water is followed by stirring at room temperature for 20 h. The pH is adjusted to pH 1 with conc. hydrochloric acid. The mixture is extracted with ethyl acetate. The organic phase is washed with water and dried over sodium sulfate. Addition of silica gel is followed by concentration and chromatography on silica gel (mobile phase: toluene/methanol/acetic acid). Concentration of the product fractions and drying in vacuo result in 1.31 g (18.2% of theory) of the title compound.

Provenance & Evidence