Water → 5-Aminoindole-1-carboxylic acid phenylamide

Participants

Reaction Conditions

Reaction Steps

5-Nitroindole-1-carboxylic acid phenylamide (3.53 g, 12.3 mmol) was dissolved in ethanol (250 ml); water (50 ml), electrolytic iron powder (2.75 g, 49.2 mmol), ammonium chloride (5.26 g, 98.4 mmol) were added thereto; and the reaction mixture was heated and stirred at 80° C. for 2 hours. After cooling to room temperature, the reaction mixture was filtered off; insoluble portions were washed with ethyl acetate; and the filtrate was concentrated under reduced pressure. The residue was partitioned between water and a solvent mixture of ethyl acetate and tetrahydrofuran; and the organic layer was washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was solidified by diethyl ether; the crystals were suspended in diethyl ether, filtered off, washed with diethyl ether, and dried to yield the title compound as pale red powder (681 mg, 2.71 mmol, 22.0%). The mother liquor was concentrated under reduced pressure, which was then treated by the similar methods to yield the title compound (590 mg, 2.35 mmol, 19.1%) as pale red powder (secondary crystals).

Provenance & Evidence