5192-23-4

Greenish-grey to tan powder

Reactant for preparation of:• ;Inhibitors of bacterial thymidylate synthase1• ;Mimetics of non-alkaloid toxin lignan anticancer and antiviral agent Podophyllotoxin (PPT)2• ;Inhibitors of Gli1-mediated transcription in the Hedgehog pathway3• ;Protein kinase C θ (PKCθ) inhibitors4• ;Indolic non-peptidic HIV protease inhibitors5• ;Transient receptor potential cation channel subfamily V member 1 (TRPV1) antagonists6• ;Cyclooxygenase-2 (COX-2) and lipoxygenase (LOX) inhibitors7• ;11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) inhibi

ChEBI: 4-Aminoindole is a member of indoles.

The Journal of Organic Chemistry, 48, p. 5130, 1983 DOI: 10.1021/jo00173a071

A. Synthesis of 4-aminoindole. Iron powder (1.20 g, 21.58 mmol) and acetic acid (2.47 mL, 43.19 mmol) were sequentially added to a solution of ethanol (20 mL) containing 4-nitroindole (1.0 g, 6.17 mmol). The reaction mixture was heated to reflux for 14 hours. After completion of the reaction, the ethanol solvent was removed by rotary evaporator. The residue was dispersed in a solvent mixture of water and ethyl acetate for extraction and separation. The ethyl acetate layer was collected and dried with anhydrous magnesium sulfate followed by filtration to remove the desiccant. The filtrate was concentrated by rotary evaporation to give the crude product. The crude product was further purified by silica gel column chromatography using 1% methanol/dichloromethane mixture as eluent. The elution fractions containing the target product were collected, combined and the solvent was removed by rotary evaporation to give 0.815 g of 4-aminoindole as an orange solid in 82% yield.

[1] Patent: US6162818, 2000, A