Acetic Acid → 4-Aminoindole

Participants

Reaction Steps

Iron powder (1.20 g, 21.58 mmol) and acetic acid (2.47 mL, 43.19 mmol) are added to a solution of 4-nitroindole (1.0 g, 6.17 mmol) in ethanol (20 mL). The resulting suspension is heated to reflux for 14 hours. The ethanol is removed by rotary evaporation and the residue is partitioned between water and ethyl acetate. The ethyl acetate layer is dried over magnesium sulfate, filtered, and the solvents removed by rotary evaporation. The crude residue is purified via silica gel column chromatography using 1% methanol/methylene chloride as the eluent. The appropriate fractions are combined and the solvents removed by rotary evaporation to yield 0.815 g of 4-aminoindole as an orange solid (82% yield).

Provenance & Evidence