Nitric Acid → Methyl 2,4-difluoro-5-nitrobenzoate

HRID 488497Notes

Reaction equation

HRID 488497 reaction equation
[N+:1]([O-:4])(O)=[O:2].S(=O)(=O)(O)O.[CH3:10][O:11][C:12](=[O:21])[C:13]1[CH:18]=[CH:17][C:16]([F:19])=[CH:15][C:14]=1[F:20]>>[CH3:10][O:11][C:12](=[O:21])[C:13]1[CH:18]=[C:17]([N+:1]([O-:4])=[O:2])[C:16]([F:19])=[CH:15][C:14]=1[F:20]

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 2782897Methyl 2,4-Difluorobenzoate

Product 1

HCID 11447263Methyl 2,4-difluoro-5-nitrobenzoate

Procedure

Fuming nitric acid 90% (8.5 mL, 0.19 mol) was added with gentle stirring to concentrated sulfuric acid 98% (125 mL) in a 1 L beaker. After stirring for 10 minutes at room temperature, 2,4-difluorobenzoic acid methyl ester (21.9 g, 0.127 mol) was added dropwise. After the addition, the reaction mixture was allowed to stir gently for 40 minutes at room temperature. The reaction mixture was then poured into ice-H2O (1 L) and stirred for 10 minutes. The mixture was extracted with EtOAc. The layers were separated, and the organic layer was washed sequentially with 1N NaCl, saturated NaHCO3, H2O and brine, dried (Na2SO4), filtered and concentrated in vacuo to afford a yellow residue. This residue was washed with 10% EtOAc/hexane, filtered, and dried to yield a pale yellow solid, 29.0 g (0.133 mol, 82%). mp 78-80° C. Analysis for C8H5F2NO4: Calcd: C, 44.25; H, 2.32; N, 6.45. Found: C, 44.18; H, 2.39; N, 6.14.

Workup

  1. additionwas added
  2. additionAfter the addition
  3. stirringto stir gently for 40 minutes at room temperature
  4. stirringstirred for 10 minutes
  5. extractionThe mixture was extracted with EtOAc
  6. customThe layers were separated
  7. washthe organic layer was washed sequentially with 1N NaCl, saturated NaHCO3, H2O and brine
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customto afford a yellow residue
  12. washThis residue was washed with 10% EtOAc/hexane
  13. filtrationfiltered
  14. customdried
  15. customto yield a pale yellow solid, 29.0 g (0.133 mol, 82%)

Sources & evidence

ORD record
ord-92a0b13a3f3e44048f753d3bd05fec1f
Source dataset
uspto-grants-2005_12
Patent number
US06972287B1

Reaction notes

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