反応 #2304275
ord-5e54a98d82144ffc983c6b0be72907d7
反応方程式
反応条件
後処理
- 1温度the reaction was subsequently heated
- 2温度at reflux for 2 hours
- 3抽出was extracted with ethyl acetate (2×200 mL)
- 4洗浄the combined organic extracts were washed with aqueous potassium hydroxide solution (˜1 M, 200 mL)
- 5乾燥dried (magnesium sulphate)
- 6濃縮concentrated under reduced pressure
- 7その他The crude product was purified by column chromatography [SiO2; light petroleum to 4:1 light petroleum-ethyl acetate]
実験手順
To a solution of 5-amino-2-methylphenol (10 g, 81.2 mmol) in hydrobromic acid (40 mL, 48% solution) and water (50 mL) at 0° C. was added a solution of sodium nitrite (5.6 g, 81.2 mmol) in water (15 mL) and the mixture stirred at this temperature for 30 minutes. To this was added copper (I) bromide (11.6 g, 81.2 mmol) in hydrobromic acid (15 mL, 48% solution) and the reaction was subsequently heated at reflux for 2 hours. Upon cooling to room temperature the resulting mixture was extracted with ethyl acetate (2×200 mL) and the combined organic extracts were washed with aqueous potassium hydroxide solution (˜1 M, 200 mL), dried (magnesium sulphate) and concentrated under reduced pressure. The crude product was purified by column chromatography [SiO2; light petroleum to 4:1 light petroleum-ethyl acetate] to give the title compound as a colourless oil, which crystallised to give fine colourless needles upon standing overnight (4 g, 26%). Rf=0.26 [4:1 light petroleum-ethyl acetate]. 1H NMR δ 2.21 (3 H, s), 4.89-4.95 (1 H, br, s), 6.96-6.97 (1 H, br, m), 6.99-7.00 (2 H, m).