Hydrochloric Acid → 3-Bromo-2-chloro-4,5-difluoroaniline

To a suspension of iron powder (38.6 g) in water (40 ml), with stirring vigorously at 50° to 60° C., was slowly added concentrated hydrochloric acid (5 ml). After mixed with ethanol (100 ml), 3-bromo-2-chloro-4,5-difluoronitrobenzene (58.8 g) was added portionwise to the suspension at 60° to 75° C. during 30 minutes. After stirring for 70 minutes, the hot reaction mixture was filtered and the insoluble materials were washed with hot ethanol (30 ml) and with benzene (100 ml) successively. The filtrate and washings were combined and mixed with ice water. The resulting organic layer was washed with water, dried over anhydrous sodium sulfate and then concentrated. The resulting residue was purified by silica gel chromatography eluting with dichloromethane-n-hexane (1:1) to give the title compound (34.5 g) as light brown prisms, mp 83°-86° C.