4-Bromo-1-fluoro-2-nitrobenzene → 4-Bromo-7-fluoroindole

Participants

Reaction Steps

To a solution of 4-bromo-1-fluoro-2-nitrobenzene (1.1 g, 5.0 mmol) in THF (20 mL) at −40° C. under nitrogen atmosphere was added slowly vinylmagnesium bromide (1 M in THF, 15.5 mL, 15.5 mmol). The reaction mixture was stirred for 1.5 h then quenched with saturated NH4Cl aqueous solution (10 mL). The mixture was partitioned between EtOAc (300 mL) and water (50 mL). The organic layer was separated, washed with brine, dried (MgSO4), filtered and evaporated in vacuo. The residue was purified by SiO2 chromatography eluting with 2.5% EtOAc/petroleum ether to afford 0.125 g (12%) of 4-bromo-7-fluoro-1H-indole (110) as brown oil: MS (ESI) m/z=214 [M−1]+.

Provenance & Evidence