Hydrochloric Acid → 3-Bromo-2,4-dichloro-5-fluoroaniline

To a suspension of iron powder (135.4 g) in water (140 ml), with vigorous stirring at 50°-60° C., was slowly added concentrated hydrochloric acid (18 ml). After ethanol (350 ml) was mixed, 3-bromo-2,4-dichloro-5-fluoronitrobenzene (218.8 g) was added portionwise to the suspension at 52°-76° C. during an hour. After stirring for 75 minutes at the same temperature, the hot reaction mixture was filtered after adding benzene (500 ml) and the insoluble material was successively washed with hot ethanol (100 ml) and benzene (200 ml). The filtrate and washings were combined. The organic layers were washed with water saturated with sodium chloride, dried over anhydrous sodium sulfate and then concentrated. The resulting residue was recrystallized from ethanol-water to give the title compound (141.6 g) as light brown needles, mp 126°-129.5° C.