Sulfuric Acid → 1-Bromo-2,5-dichloro-3-nitrobenzene

Beteiligte Stoffe

Reaktionsschritte

Concentrated sulphuric acid (2.2 ml) was slowly added to a suspension of 2-bromo-3,5-dichloro-4-nitroaniline (D8) (0.9 g, 3.1 mmol) in ethanol (20 ml). The resulting solution was heated to reflux and crushed sodium nitrite (478 mg, 6.9 mmol) was added in two portions. After 0.5 h at reflux, the mixture was cooled, diluted with dichloromethane (50 ml) and saturated sodium hydrogen carbonate solution (50 ml) was added. The layers were separated and the organic phase dried (Na2SO4) and concentrated to an oil which was purified by column chromatography over silica gel eluting with a gradient of ethyl acetate/hexane to give the title compound (D9) as an orange solid (0.67 g, 80%), MH+ 269/271.

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