Phenylacetaldehyde → 3-Phenylindole

Participants

Reaction Steps

A solution of phenylhydrazine (1 mL, 10.15 mmol) and phenylacetaldehyde (1.32 mL, 10.15 mmol) in acetic acid was refluxed for 6 hours under a nitrogen atmosphere. After cooling to room temperature, the reaction mixture was poured into a saturated aqueous solution of sodium carbonate (100 mL) at 0° C. After extraction with dichloromethane (2×30 mL), the organic layer was dried over sodium sulfate, filtered and evaporated to dryness. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 90/10) to afford the desired indole (1a) as a pale oil (940 mg, 4.86 mmol, 48%).

Provenance & Evidence