Sodium Hydroxide → 2-Fluoro-4-nitrobenzoic acid

HRID 369772Notes

Reaction equation

HRID 369772 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][C:3]=1[CH3:11].[OH-:12].[Na+].[O-:14][Mn](=O)(=O)=O.[K+]>>[F:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[CH:4][C:3]=1[C:11]([OH:14])=[O:12]

Participants

4

Reactant 3

HCID 14798Sodium HydroxideHCID 740252-Fluoro-4-nitrotolueneHCID 516875Potassium Permanganate2×

Product 1

HCID 3026792-Fluoro-4-nitrobenzoic acidYield 42%

Conditions

Temperature
95 °C

Procedure

A 3L 3-necked flask equipped with a magnetic stirrer was charged with 25.00 g of 2-fluoro-4-nitrotoluene (Aldrich Chemical Co., Milwaukee, Wis., 53233), 1.65 L of 1 N NaOH, and 25.00 g of KMnO4. The resulting mixture was heated to 95° C. with stirring. Additional 25.00 g portions of KMnO4 were added after 1 h and 2 h. After stirring at 95° C. for an additional hour the reaction mixture was cooled to RT and filtered through celite to remove MnO2. The filtrate was concentrated in vacuo to 500 mL and acidified to pH 2 by addition of concentrated H2SO4. A yellow-orange precipitate formed which was collected by vacuum filtration. The crude solid was dissolved in 300 mL of 1 N aqueous NaOH, acidified to pH 2 and the mixture extracted with CH2Cl2 (4×150 mL). The combined CH2Cl2 extracts were washed with 0.1 N aqueous HCl (2×100 mL), dried over anhydrous Na2SO4, and concentrated in vacuo to afford 12.44 g (42%) of 2-fluoro-4-nitrobenzoic acid as a yellow crystalline solid, m.p. 165-167° C.

Workup

  1. stirringAfter stirring at 95° C. for an additional hour the reaction mixture
  2. temperaturewas cooled to RT
  3. filtrationfiltered through celite
  4. customto remove MnO2
  5. concentrationThe filtrate was concentrated in vacuo to 500 mL
  6. additionacidified to pH 2 by addition of concentrated H2SO4
  7. customA yellow-orange precipitate formed which
  8. filtrationwas collected by vacuum filtration
  9. dissolutionThe crude solid was dissolved in 300 mL of 1 N aqueous NaOH
  10. extractionthe mixture extracted with CH2Cl2 (4×150 mL)
  11. washThe combined CH2Cl2 extracts were washed with 0.1 N aqueous HCl (2×100 mL)
  12. dry with materialdried over anhydrous Na2SO4
  13. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-47102f4aecd34ee984badfb0ff8ef643
Source dataset
uspto-grants-2000_10
Patent number
US06140100

Reaction notes

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