Sulfuric Acid → 2,5-Difluoro-4-nitroaniline

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence