HCID 14064733, compound → 4-Fluoroindole-2-carboxylic acid

Participants

Reaction Steps

A solution of 32 (4.8 g, 31 mmol) in 4% NH4OH (60 mL) was added to a suspension of ferrous hydroxide that was prepared from ferrous sulfate heptahydrate (52.45 g, 188.7 mmol) and concentrated NH4OH (23 mL) in water (200 mL). The mixture was maintained at the boiling point for five minutes. The ferric hydroxide was separated by filtration and washed repeatedly with dilute NH4OH and water. The filtrate was acidified with dilute HCl. The resulting solid was collected by filtration to afford 1.2 g (22%) of 4-fluoro-1H-indole-2-carboxylic acid (34) as a white solid, which was used in the next step without further purification.

Provenance & Evidence