反应详情

温度

40 °C

122 g (1 mol) of 2,4-Diaminotoluene and 1782 g (20 mol) of ethyl carbamate are heated to 200° C. in the presence of 320 g of ethanol, with stirring, in a 5-liter stirrer autoclave, and 1300 ml of an ammonia/ethanol mixture are distilled off per hour. The autoclave is adjusted to a pressure of from 6 to 10 bar by means of a control valve and the ethanol concentration is kept constant by pumping in fresh ethanol. After a reaction time of 5 hours, the autoclave is left to cool down, emptied, and the alcohol is distilled at 40° to 90° C./90 mbar. The distillation residue (1224 g) is taken up with 1200 g of water at 95° C. and intensively stirred. 260 g of 2,4-bis-(ethoxycarbonylamino)-toluene precipitate after cooling of the solution to 40° C. and are filtered off. The 2,4-bis-(ethoxycarbonylamino)-toluene is again taken up with 300 g of boiling water, and reprecipitated at 40° C. 170.4 g (64.1% of theoretical) of 2,4-bis-(ethoxycarbonylamino)-toluene are obtained after drying over night in a drying cupboard at 90° C./100 mbar.

1. distillationare distilled off per hour
2. customThe autoclave is adjusted to a pressure of from 6 to 10 bar by means of a control valve
3. concentrationthe ethanol concentration
4. temperatureto cool down
5. distillationthe alcohol is distilled at 40° to 90° C./90 mbar
6. customis taken up with 1200 g of water at 95° C.
7. filtrationare filtered off
8. customreprecipitated at 40° C