反应详情

温度

5 °C

Ethyl 4-amino-3-methylbenzoate (3.85 g; 21.5 mmol) was dissolved in hot, 35% H2SO4 /water and the mixture then cooled to below 5° C. An ice-cold solution of 1.91 g (22.5 mmol) of sodium nitrite in 20 ml of water was then slowly added to the mixture such that the temperature of the mixture never exceeded 5° C. The mixture was stirred at 5° C. for 10 minutes and then treated with 1 g of urea and stirred for a further 10 minutes. A solution of 50 g (207 mmol) of cupric nitrate trihydrate in 750 ml of water was added to the reaction mixture followed by 2.87 g of cuprous oxide. The mixture was stirred for a further 15 minutes and then extracted with 3×300 ml ether. The ether extracts were combined and then washed with water and saturated NaCl solution and then dried (MgSO4). The solution was filtered, the solvent removed in-vacuo and the residue purified by flash chromatography (silica; 13% ethyl acetate in hexanes to 20% ethyl acetate in hexanes) to give the title compound as a pale yellow solid.

1. temperaturethe mixture then cooled to below 5° C
2. stirringstirred for a further 10 minutes
3. stirringThe mixture was stirred for a further 15 minutes
4. extractionextracted with 3×300 ml ether
5. washwashed with water and saturated NaCl solution
6. dry with materialdried (MgSO4)
7. filtrationThe solution was filtered
8. customthe solvent removed in-vacuo
9. customthe residue purified by flash chromatography (silica; 13% ethyl acetate in hexanes to 20% ethyl acetate in hexanes)