Sulfuric Acid → 3-Cyano-4-fluorobenzoic acid

HRID 1821016Notes

Reaction equation

HRID 1821016 reaction equation
[C:1]([C:3]1[CH:4]=[C:5]([CH:8]=[CH:9][C:10]=1[F:11])[CH:6]=[O:7])#[N:2].S(=O)(=O)(O)[OH:13]>O.CC(C)=O.[O-2].[Cr+3].[O-2].[O-2].[Cr+3]>[C:1]([C:3]1[CH:4]=[C:5]([CH:8]=[CH:9][C:10]=1[F:11])[C:6]([OH:13])=[O:7])#[N:2]

Participants

6

Reactant 2

HCID 1118Sulfuric AcidHCID 27695822-Fluoro-5-formylbenzonitrile

Product 1

HCID 27739323-Cyano-4-fluorobenzoic acid

Reagents, catalysts & solvents 3

HCID 165971Chromium oxideCatalystHCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

Chromium oxide (14.77 mmol; 1.48 g) was dissolved in a solution of sulfuric acid (1.1 mL) and water (3.4 mL) at 0° C. To this solution was added to a mixture of 3-cyano-4-fluorobenzaldehyde (13.4 mmol; 2.0 g) in acetone (17 mL) at 0° C. The reaction mixture was warmed to rt and stirred for 6 h. The reaction was then quenched with methanol (20 mL) and water (50 mL) and the product was extracted with EtOAc (2×50 mL). The combined organics were washed with brine (50 mL), dried over magnesium sulfate, filtered and concentrated in vacuo to yield 2.25 g of product: 1H NMR (500 MHZ, CDCl3) δ 8.39 (d, J=5.0, 1H), 8.28-8.29 (m, 1H), 7.64 (t, J=8.9, 1H).

Workup

  1. customThe reaction was then quenched with methanol (20 mL) and water (50 mL)
  2. extractionthe product was extracted with EtOAc (2×50 mL)
  3. washThe combined organics were washed with brine (50 mL)
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-28908288e27d4d25b727d061139f3893
Source dataset
uspto-grants-2009_10
Patent number
US07605171B2

Reaction notes

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