反应详情

温度

50 °C

5.32 kg of 1-phenylpropane-1,2-dione (98.6% by G.C. equivalent to 5.24 kg, 35.4 mole) were dissolved in 36 liters of chloroform and the solution was heated to 50° C. A solution of 5.66 kg (35.4 mole) of bromine in 8 liters of chloroform was added slowly to maintain a gentle reflux and immediate decolorization of the bromine (approximately 6 hours). The solution was cooled to room temperature overnight and was washed with 20 liters of saturated sodium bicarbonate solution and 20 liters of water and dried over sodium sulfate. The solvent was removed under vacuum to obtain 8.2 kg (100% yield) of a green/yellow oil which was used directly for subsequent reactions after estimation of its purity (approximately 75% by G.C. or N.M.R.).

1. temperatureto maintain
2. temperaturea gentle reflux
3. temperatureThe solution was cooled to room temperature overnight
4. washwas washed with 20 liters of saturated sodium bicarbonate solution and 20 liters of water
5. dry with materialdried over sodium sulfate
6. customThe solvent was removed under vacuum