4-Bromo-2-nitrotoluene → Benzoic Acid

HRID 1294626Notes

Reaction equation

HRID 1294626 reaction equation
Br[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[C:4]([N+]([O-])=O)[CH:3]=1.BrC1C=CC(C)=C([N+]([O-])=O)C=1.[O-][Mn](=O)(=O)=O.[K+]>O=[Mn]=O.O>[C:6]([OH:8])(=[O:7])[C:5]1[CH:9]=[CH:10][CH:2]=[CH:3][CH:4]=1

Participants

6

Reactant 3

HCID 1235464-Bromo-2-nitrotolueneHCID 516875Potassium PermanganateHCID 37744674-Bromo-2-nitrobenzoic acid

Product 1

HCID 243Benzoic AcidYield 22%

Reagents, catalysts & solvents 2

HCID 14801Manganese dioxideCatalystHCID 962WaterSolvent

Procedure

4-Bromo-2-nitrobenzoic acid. A mixture of 4-bromo-2-nitrotoluene (5.0 g, 23 mmol), KMnO4 (10.9 g, 69 mmol), and water (250 mL) was heated at reflux overnight in a 1 L round-bottom flask fitted with a reflux condenser. The brown suspended MnO2 was removed by filtration through a pad of diatomaceous earth. The filter cake was washed with water. The basic filtrate was acidified to pH˜1 with concentrated HCl and extracted with EtOAc (3×300 mL). The combined organic layers were dried (MgSO4) and concentrated in vacuo to provide pure benzoic acid (1.22 g, 22%). 1H NMR (400 MHz, CD3OD): 8.07 (d, J=1.9 Hz, 1H), 7.85 (dd, J=8.2, 1.9 Hz, 1H), 7.65 (d, J=8.2 Hz, 1H). MS (ESI): neg. ion m/z 244 [M−H]−.

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight in a 1 L round-bottom flask
  3. customfitted with a reflux condenser
  4. customwas removed by filtration through a pad of diatomaceous earth
  5. washThe filter cake was washed with water
  6. extractionextracted with EtOAc (3×300 mL)
  7. dry with materialThe combined organic layers were dried (MgSO4)
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-8e4f31d5872e4da985b4814ca6219aa8
Source dataset
uspto-grants-2007_07
Patent number
US07241759B2

Reaction notes

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