Reaktion #4330

Reaktionsgleichung

hydrochloric acid

2,5-difluoroaniline

pyridine

benzenesulphonyl chloride

→

2,5-difluoro-N-benzenesulphonylaniline

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeis between 35° C. and 45° C
2. 2
   workup.ADDITIONafter the addition
3. 3
   workup.ADDITIONhave been added
4. 4
   SonstigeThe expected product precipitates
5. 5
   FiltrationAfter filtration
6. 6
   Waschenwashing
7. 7
   workup.ADDITIONit is treated with a normal sodium hydroxide solution in order
8. 8
   Sonstigeto remove insoluble material
9. 9
   SonstigeThe expected product, which has precipitated
10. 10
    Filtrationis filtered off
11. 11
    Waschenwashed to neutrality
12. 12
    Sonstigerecrystallized from acetic acid

Vorschrift

0.194 mole (25 g) of 2,5-difluoroaniline is added to 125 ml of pyridine. 0.2 mole (25.5 ml) of benzenesulphonyl chloride is added, while the temperature is between 35° C. and 45° C. The temperature is maintained at 40° C. for 1 hour after the addition is completed, and then the reaction mixture is poured onto 1 kg of ice and water to which 100 ml of concentrated hydrochloric acid have been added. The expected product precipitates. After filtration and washing, it is treated with a normal sodium hydroxide solution in order to remove insoluble material. The soda-containing filtrate is neutralized with concentrated hydrochloric acid. The expected product, which has precipitated, is filtered off, washed to neutrality and recrystallized from acetic acid. It melts at 115° C.

Quelle