Potassium Fluoride → 2-Chloro-4,5-difluorobenzoic acid

HRID 1683429Notes

Reaction equation

[Cl:1][C:2]1[CH:10]=[C:9]([N+]([O-])=O)[C:8]([F:14])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[F-:15].[K+]>C1S(=O)(=O)CCC1>[Cl:1][C:2]1[CH:10]=[C:9]([F:15])[C:8]([F:14])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]

Participants

Conditions

Temperature: 150 °C

Procedure

The combined benzoic acids made in each of Examples 3, 11 and 12 (consisting of compounds 5 and 6 in a ratio of about 2:1) were converted to the corresponding acid chlorides as in Example 4. The acid chlorides (2 g, 8.4 mmol) were dissolved in 4 ml of tetramethylenesulfone and treated with spray-dried KF (2.0 g, 34.5 mmol). The mixture was heated at 150° C. under nitrogen for 3 hours and the product distilled at 70°-75° C./15 mm. The acid fluoride collected was hydrolyzed with water and the product was dried in vacuum to give pure compound 8 as the only product (0.4 g, 24%).

Workup

distillationthe product distilled at 70°-75° C./15 mm
customThe acid fluoride collected
customthe product was dried in vacuum

Sources & evidence

ORD record: ord-862207d5a46d4b258add97e279eb3997
Source dataset: uspto-grants-1997_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05637765

Reaction notes

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