反应详情

To a solution of 4-ethyl-2-nitroaniline (28 g) in acetic acid (250 ml) was added bromine (9.64 ml) dropwise with stirring at room temperature. The reaction mixture was stirred for 1 hour, poured into water, and extracted with ethyl acetate (3×200 ml). The organic layer was washed with water (3×200 ml), brine (2×100 ml), dried over magnesium sulphate and evaporated to yield 2-bromo-4-ethyl-6-nitroaniline (38 g). This was dissolved in ethanol (200 ml), concentrated sulphuric acid (24 ml) was added dropwise, the mixture heated to reflux and solid sodium nitrate (27 g) added in small amounts over 30 minutes. The reaction mixture was refluxed for a further 1 hour, cooled and poured into ice water. The product was extracted into ethyl acetate which was washed with water (2×100 ml). brine (2×100 ml), dried over magnesium sulphate and evaporated to yield 3-bromo-5-ethyl-nitrobenzene (35.5 g), δ (60 MHz, CDCl3), 1.3 (3H, t, CH3), 2.8 (2H, q, CH2) 7.6 (1H, s, 4-H), 7.9 (1H, s. 6-H) and 8.0 (1H, s, 2H).

1. stirringThe reaction mixture was stirred for 1 hour
2. extractionextracted with ethyl acetate (3×200 ml)
3. washThe organic layer was washed with water (3×200 ml), brine (2×100 ml)
4. dry with materialdried over magnesium sulphate
5. customevaporated