Diethyl Ether → 3-Bromo-2,4-difluoroaniline

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-bromo-1,3-difluoro-4-nitrobenzene (30 g, 130 mmol) and tin(II) chloride dihydrate in 36% hydrochloric acid (150 ml) was heated to 40° C. Diethyl ether (20 ml) was slowly added to bring about solution. Once in solution the reaction proceeded rapidly and the ether boiled away. After heating at 60° C. for 1 h the reaction was cooled and then poured onto ice-water (1.5 l). The solution was made basic (pH 13) with 30% aq. sodium hydroxide keeping the internal temperature below 20° C. The resulting grey slurry was swirled with chloroform (2×500 ml), the organic extracts were combined, washed with water, dried over anhydrous magnesium sulfate containing 2 g decolourising charcoal, filtered and evaporated to dryness. Trituration with isohexane afforded 3-bromo-2,4-difluorophenylamine as a buff-coloured solid (23 g, 85%): δH (360 MHz, CDCl3) 3.51 (2H, br), 6.65-6.70 (1H, m), 6.75-6.80 (1H, m).

Provenance & Evidence