Reaktion #4332

Reaktionsgleichung

sulphuric acid

2,5-difluoro-4-nitro-N-benzenesulphonylaniline

→

2,5-difluoro-4-nitroaniline

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigerises to 70° C
2. 2
   workup.ADDITIONis then added
3. 3
   Sonstigethe expected product precipitates
4. 4
   FiltrationAfter filtration
5. 5
   Waschenwashing to neutrality the product
6. 6
   Sonstigeis recrystallized from 100 ml of 96° ethanol

Vorschrift

10 ml of water are added with due care to 75 ml of concentrated sulphuric acid; the temperature rises to 70° C. 0.105 mole (33 g) of 2,5-difluoro-4-nitro-N-benzenesulphonylaniline prepared in the previous stage is then added. The temperature is maintained at 70° C. for 2 hours. The reaction mixture is poured onto 1 kg of ice and water and the expected product precipitates. After filtration and washing to neutrality the product is recrystallized from 100 ml of 96° ethanol. It melts at 153° C.

Quelle