N-bromobutanimide → 2-Bromo-5-fluoro-4-nitroaniline

Participants

Reaction Conditions

Reaction Steps

A flask was charged with 3-fluoro-4-nitroaniline (1.0 equiv) followed by ethyl acetate (10 vol) and stirred to dissolve all solids. N-Bromosuccinimide (1.0 equiv) was added as a portion-wise as to maintain internal temperature of 22° C. At the end of the reaction, the reaction mixture was concentrated in vacuo on a rotavap. The residue was slurried in distilled water (5 vol) to dissolve and remove succinimide. (The succinimide can also be removed by water workup procedure.) The water was decanted and the solid was slurried in 2-propanol (5 vol) overnight. The resulting slurry was filtered and the wetcake was washed with 2-propanol, dried in vacuum oven at 50° C. overnight with N2 bleed until constant weight was achieved. A yellowish tan solid was isolated (50% yield, 97.5% AUC). Other impurities were a bromo-regioisomer (1.4% AUC) and a di-bromo adduct (1.1% AUC). 1H NMR (500 MHz, DMSO) δ 8.19 (1H, d, J=8.1 Hz), 7.06 (br. s, 2H), 6.64 (d, 1H, J=14.3 Hz).

Provenance & Evidence