Nitric Acid → 2,4-Difluoro-5-nitrobenzoic acid

HRID 341889Notes

Reaction equation

HRID 341889 reaction equation
[F:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[N+:12]([O-])([OH:14])=[O:13]>S(=O)(=O)(O)O>[F:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([N+:12]([O-:14])=[O:13])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 741022,4-Difluorobenzoic acid

Product 1

HCID 27828222,4-Difluoro-5-nitrobenzoic acidYield 61%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

2,4-Difluorobenzoic acid (5 g, 0.031M) was dissolved in concentrated sulfuric acid (30 ml), and cooled to 0°. The mixture was stirred, and fuming nitric acid (d 1.567 g/ml, 1.91 ml, 0.047M) added dropwise, keeping the temperature below 5°. After stirring for 3 hours, the mix was poured onto ice, and organics extracted into dichloromethane (2×75 ml). The combined organic layers were washed with water, dried (MgSO4), and evaporated to give 2,4-difluoro-5-nitrobenzoic acid (3.9 g, 61%). Nmr (DMSO-d6): δ 7.18 (t, 1H); 8.88 (t, 1H); 9.93 (br, 1H).

Workup

  1. temperaturecooled to 0°
  2. customthe temperature below 5°
  3. stirringAfter stirring for 3 hours
  4. additionthe mix was poured onto ice
  5. extractionorganics extracted into dichloromethane (2×75 ml)
  6. washThe combined organic layers were washed with water
  7. dry with materialdried (MgSO4)
  8. customevaporated

Sources & evidence

ORD record
ord-c219852bd3364d7d9618180a088bfc69
Source dataset
uspto-grants-1999_01
Patent number
US05856321

Reaction notes

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