Reaction #710561

Reaction equation

2′,4′-Difluorobiphenyl-4-sulphonic acid

DMF

thionyl chloride

→

title compound

2′,4′-Difluorobiphenylsulfonyl chloride

Conditions

Workup

1. 1
   TemperatureThe mixture was heated
2. 2
   Temperatureat reflux for 30 minutes
3. 3
   Temperaturethe reaction mixture was heated
4. 4
   Temperatureat reflux for a further 4 hours
5. 5
   TemperatureThe reaction mixture was then cooled
6. 6
   Otherthe thionyl chloride evaporated
7. 7
   Otherthe residue was then azeotroped with toluene (3×10 mL)
8. 8
   Washwashed with water (50 mL) and brine (50 mL)
9. 9
   Dryingdried over MgSO4
10. 10
    FiltrationFiltration and evaporation

Procedure

2′,4′-Difluorobiphenyl-4-sulphonic acid (12.1 g, 47 mmol) was suspended in thionyl chloride (100 mL). The mixture was heated at reflux for 30 minutes, when a catalytic amount of dry DMF was added and the reaction mixture was heated at reflux for a further 4 hours. The reaction mixture was then cooled, the thionyl chloride evaporated and the residue was then azeotroped with toluene (3×10 mL). The resulting yellow/orange gum was taken up into EtOAc (250 mL) and washed with water (50 mL) and brine (50 mL), and dried over MgSO4. Filtration and evaporation gave the title compound as a brown oil which crystallized on standing (11 g).

Source