Sulfuric Acid → 3-Hydroxy-5-nitrobenzoic acid

HRID 1370512Notes

Reaction equation

HRID 1370512 reaction equation
C[O:2][C:3](=[O:14])[C:4]1[CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=[C:6](N)[CH:5]=1.[OH:15]S(O)(=O)=O.N([O-])=O.[Na+].[NH4+].[OH-]>O>[OH:15][C:6]1[CH:5]=[C:4]([CH:9]=[C:8]([N+:10]([O-:12])=[O:11])[CH:7]=1)[C:3]([OH:2])=[O:14]

Participants

6

Reactant 4

HCID 1118Sulfuric Acid2×HCID 14923Ammonium HydroxideHCID 2756518Methyl 3-amino-5-nitrobenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 8203933-Hydroxy-5-nitrobenzoic acidYield 39%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent3×

Procedure

To a solution of 3-amino-5-nitro-benzoic acid methyl ester (Example 313, 1.96 g, 10 mmol) in 23 mL of H2O and 5 mL of con. H2SO4 at 0° C., was added a solution of NaNO2 (Aldrich, 900 mg, 13 mmol) in 9 mL of H2O. After 50 min stirring, the resulting diazonium salt was added to a solution of 17 mL of H2O and 17 mL of con. H2SO4 at 90° C. After stirred at 90 ° C. for 90 min, the mixture was cooled to room temperature and brought to pH 3 with con. NH4OH. The mixture was extracted 3× with EtOAc (100 mL). The organic layers were washed twice with a brine solution (100 mL), dried over Na2SO4 and concentrated. The residue was purified by chromatography (5%-10% MeOH/CH2Cl2) to give 705 mg (39%) of product.

Workup

  1. customat 90° C
  2. stirringAfter stirred at 90 ° C. for 90 min
  3. extractionThe mixture was extracted 3× with EtOAc (100 mL)
  4. washThe organic layers were washed twice with a brine solution (100 mL)
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated
  7. customThe residue was purified by chromatography (5%-10% MeOH/CH2Cl2)

Sources & evidence

ORD record
ord-cf50cbd5bc2f4233ab44dec0117d4598
Source dataset
uspto-grants-2003_06
Patent number
US06583157B2

Reaction notes

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