反应详情

温度

42.5 °C

520 parts of toluene, 423 parts (3 mol) of 4-fluoronitrobenzene, 192 parts (3.3 mol) of acetone and 8 parts of catalyst (5% Pt on charcoal, water-moist, water content 50%) are placed in a hydrogenation autoclave. After the gas space has been flushed three times with each of nitrogen and hydrogen, the mixture is heated to from 80°=0 to 85° C. with stirring and reduced at a hydrogen pressure of from 0.2 to 1.0 MPa. When after about 2 hours the uptake of hydrogen falls sharply, the pressure is raised to 2.0 MPa and stirring is continued at 85° C for 30 minutes until there is no longer any drop in pressure. The batch is cooled to 60° C., the autoclave is let down and flushed with nitrogen, and the catalyst is filtered off on a pressure filter at from 50° to 60° C. The aqueous phase is separated off from the filtrate and toluene is distilled off until the water content of the solution is <0.02%. The solution is processed further in accordance with Example 2.

1. customAfter the gas space has been flushed three times with each of nitrogen and hydrogen
2. temperaturethe pressure is raised to 2.0 MPa
3. stirringstirring
4. waitis continued at 85° C for 30 minutes until there
5. temperatureThe batch is cooled to 60° C.
6. customflushed with nitrogen
7. filtrationthe catalyst is filtered off on a pressure
8. filtrationfilter at from 50° to 60° C
9. customThe aqueous phase is separated off from the filtrate and toluene
10. distillationis distilled off until the water content of the solution