反应详情

To a solution of ethyl 4-amino-3-nitrobenzoate (D212) (21.0 g, 100 mmol, 1 equiv) in CH2Cl2 (500 ml) at room temperature was added bromine (6.7 ml, 130 mmol, 1.3 equiv) and the resulting mixture was refluxed for 4 h then bromine (2 ml, 40 mmol, 0.4 equiv) was added and the resulting mixture refluxed for another 3 h then cooled to room temperature. The organic phase was washed twice with a 10% aqueous Na2S2O3 solution and twice with H2O, dried over MgSO4 and concentrated in vacuo to give ethyl 4-amino-3-bromo-5-nitrobenzoate (D213) (27.1 g, 94%) as a yellow solid which was used in the next step without further purification.

1. temperaturethe resulting mixture was refluxed for 4 h
2. temperaturethe resulting mixture refluxed for another 3 h
3. washThe organic phase was washed twice with a 10% aqueous Na2S2O3 solution and twice with H2O
4. dry with materialdried over MgSO4
5. concentrationconcentrated in vacuo