反应详情

温度

60 °C

4-(4-Methoxyphenyl)pyridine (1 g, 5.4 mmol) was dissolved in glacial acetic acid (6 ml). Iron powder (30 mg, 0.54 mmol) was added followed by a solution of bromine (0.36 ml) in glacial acetic acid (3 ml) slowly over 5 minutes. The resulting solution was stirred at 60° C. for 1 hour. A solution of bromine (0.13 ml) in glacial acetic acid (1 ml) was added and stirring was continued at 60° C. for 1.5 hours. The solution was allowed to cool to ambient temperature, diluted with water (20 ml). Excess bromine was destroyed by adding in sold sodium bisulphite until all the colour had disappeared. Solid sodium carbonate was added until the solution was basic and the resulting solution was then extracted with ethyl acetate (2×30 ml) and dried over sodium sulphate. Removal of the solvent gave an oil which was chromatographed on silica gel in diethyl ether giving the title compound as a clear oil (0.77 g, 54%). 1H NMR (250 MHz, CDCl3) δ 8.66-8.62 (2H, d, J=8.6 Hz), 7.87-7.86 (1H, d, J=2.2 Hz), 7.61-7.56 (1H, dd, J=8.5 Hz and 2.2 Hz), 7.48-7.46 (1H, d, J=8.5 Hz), 7.03-6.99 (2H, d, J=8.6 Hz), and 3.96 (3H, s). m/z (ES+) 264, 266 (M+1).

1. stirringstirring
2. waitwas continued at 60° C. for 1.5 hours
3. temperatureto cool to ambient temperature
4. customExcess bromine was destroyed
5. additionby adding in sold sodium bisulphite until all the colour
6. additionSolid sodium carbonate was added until the solution
7. extractionthe resulting solution was then extracted with ethyl acetate (2×30 ml)
8. dry with materialdried over sodium sulphate
9. customRemoval of the solvent
10. customgave an oil which
11. customwas chromatographed on silica gel in diethyl ether giving the title compound as a clear oil (0.77 g, 54%)