4-Bromo-1H-indole-3-carbaldehyde → 4-Bromo-3-methyl-1H-indole

Participants

Reaction Steps

To a refluxing solution of 4-bromo-1H-indole-3-carbaldehyde (644 mg, 2.87 mmol) in dry THF (20 mL) was added LiAlH4 (218 mg, 5.75 mmol) in several small portions. Heating at reflux was continued for 1 h, the reaction cooled to RT and quenched with water (220 μL), 15% aq. NaOH (w/w, 220 μL), and water (650 μL). The resulting precipitate was filtered and the filtrate was concentrated under reduced pressure to dryness. To the residue was added aq. NaOH (10 mL) and the solution twice extracted with DCM (2×10 mL). The combined extracts were dried (MgSO4), filtered and concentrated in vacuo to afford 454 mg (75%) of 4-bromo-3-methyl-1H-indole (230) as light brown oil: MS (ESI) m/z=210.1 [M+1]+

Provenance & Evidence