Sulfuric Acid → 3-Chloro-5-ethylnitrobenzene

Beteiligte Stoffe

Reaktionsschritte

To 6-chloro-4-ethyl-2-nitroaniline (5.3 g) in ethanol (40 ml) was added c.H2SO4 (5 ml) dropwise. The solution was heated to reflux and solid NANO2 (4.55 g) was added in small portions over 25 minutes. After a further 1 h at reflux the mixture was poured onto ice and extracted with ethyl acetate. The organic phase was washed with water (×3) and brine (×3), dried over MGSO4 and evaporated. 3-Chloro-5-ethylnitrobenzene was isolated as a yellow oil (4.0 g) after silica chromatography. δ (60 MHz, CDCl3) 1.2 (3H, t, CH3), 2.5 (2H, q, CH2), 7.5 (1H, s, Ar) and 7.9 (2H, s, Ar). This product was treated with iron powder (2.7 g) in acetic acid (40 ml) and ethanol (30 ml) at reflux for 2.5 h. The mixture was filtered through celite and the solvent evaporated. The residual oil was diluted with hexane (2 ml) and chromatographed on silica, eluting with 20% CHCl3 /hexane. 3-Chloro-5-ethylaniline (0.9 g) was isolated as a pure oil. δ (360 MHz, CDCl3) 1.19 (3H, t, CH3), 2.52 (2H, q, CH2), 3.20 (2H, s, NH2), 6.38 (1H, dd, Ar), 6.49 (1H, dd, Ar) and 6.58 (1H, dd, Ar).

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