Sulfuric Acid → 2-Chloro-4,5-difluorobenzoic acid

HRID 374613

Reaction equation

HRID 374613 reaction equation
[NH4+].[NH4+].[O-]S(OOS([O-])(=O)=O)(=O)=O.[Cl:13][C:14]1[CH:27]=[C:26]([F:28])[C:25]([F:29])=[CH:24][C:15]=1[C:16](C1C=CC=CC=1)=[O:17].S(=O)(=O)(O)[OH:31]>C(O)(=O)C>[Cl:13][C:14]1[CH:27]=[C:26]([F:28])[C:25]([F:29])=[CH:24][C:15]=1[C:16]([OH:17])=[O:31]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 62648Ammonium PersulfateHCID 704945(2-Chloro-4,5-difluorophenyl)(phenyl)methanone

Product 1

HCID 7371712-Chloro-4,5-difluorobenzoic acidYield 80.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
90 °C

Procedure

8 g of ammonium peroxodisulfate are introduced into 5 g (19.8 mmol ) of 2-chloro-4,5-difluorobenzophenone and 20 g of glacial acetic acid and the mixture is heated at 90° C. (12 h). 100 g of 70% sulfuric acid are then added and the mixture is heated for 2 h at 150° C. Dilution with 200 g of water and filtration gives 3.1 g (16.0 mmol, 81%) of 2-chloro-4,5-difluorobenzoic acid (purity (GC) ca. 92%). Recrystallization from water gives 2.5 g of product melting at 104° C.-105° C.

Workup

  1. temperaturethe mixture is heated for 2 h at 150° C
  2. filtrationDilution with 200 g of water and filtration

Sources & evidence

ORD record
ord-57ce944fb97645a09a59dd154d8b1826
Source dataset
uspto-grants-1996_01
Patent number
US05481032

Linked notes

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