Iodine → Benzoyl chloride, 2,3-dichloro-4,5-difluoro-

HRID 2259451Notes

Reaction equation

HRID 2259451 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([F:12])=[CH:7][C:3]=1[C:4]([Cl:6])=[O:5].[Cl:13]S(O)(=O)=O.II.S(Cl)(Cl)=O>O>[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([F:12])=[CH:7][C:3]=1[C:4]([Cl:6])=[O:5].[Cl:1][C:2]1[C:10]([Cl:13])=[C:9]([F:11])[C:8]([F:12])=[CH:7][C:3]=1[C:4]([Cl:6])=[O:5]

Participants

7

Reactant 4

HCID 807IodineHCID 24386Thionyl ChlorideHCID 24638Chlorosulfonic acidHCID 101982172-Chloro-4,5-difluorobenzoyl chloride

Product 2

HCID 101982172-Chloro-4,5-difluorobenzoyl chlorideYield 22%HCID 10999320Benzoyl chloride, 2,3-dichloro-4,5-difluoro-Yield 71%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

211 g (1 mol) of 2-chloro-4,5-difluorobenzoyl chloride are introduced into 500 g of chlorosulfonic acid, and 3 g of iodine are added. The mixture is chlorinated (10 l/h) for 1.7 h at 40° C. and then diluted with water (500 g), with stirring, the temperature being allowed to rise to 80° C. In this procedure, the acid chlorides initially present in the solvent are hydrolyzed in 2 h to the carboxylic acids, which are isolated by filtration after cooling to 0° C. After drying, the mixture is reacted with thionyl chloride (2 mol) at 80° C. and excess thionyl chloride is then distilled off. The mixture is then distilled, as indicated in Example 1, to give 46.4 g (0.22 mol, 22%) of 2-chloro-4,5-difluorobenzoyl chloride and 174.9 g (0.71 mol, 71%) of 2,3-dichloro-4,5-difluorobenzoyl chloride.

Workup

  1. additionare added
  2. customfor 1.7 h
  3. customat 40° C.
  4. customto rise to 80° C
  5. customare isolated by filtration
  6. customAfter drying
  7. distillationexcess thionyl chloride is then distilled off
  8. distillationThe mixture is then distilled

Sources & evidence

ORD record
ord-a6e320b5fd6e4311a824435fe9c45d75
Source dataset
uspto-grants-1995_12
Patent number
US05473095

Reaction notes

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