Methyl 3-amino-5-bromobenzoate → 3-Bromo-5-hydroxybenzoic acid

HRID 2420904Notes

Reaction equation

HRID 2420904 reaction equation
N[C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([Br:12])[CH:11]=1)[C:5]([O:7]C)=[O:6].N([O-])=[O:14].[Na+]>O.OS(O)(=O)=O>[Br:12][C:10]1[CH:9]=[C:4]([CH:3]=[C:2]([OH:14])[CH:11]=1)[C:5]([OH:7])=[O:6]

Participants

5

Reactant 2

HCID 18763420Methyl 3-amino-5-bromobenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 157355113-Bromo-5-hydroxybenzoic acidYield 78%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 1118Sulfuric AcidSolvent2×

Procedure

To a stirred solution of methyl 3-amino-5-bromobenzoate (5.2 g, 23 mmol) in water (80 mL) and H2SO4 (60 mL) was added dropwise a solution of NaNO2 (1.9 g, 28 mmol) in water (10 mL) at 0° C. The reaction mixture was added to a mixture of water (180 mL) and H2SO4 (240 mL). The mixture was heated at reflux for 30 minutes before being cooled to room temperature. The resulting mixture was poured into crushed ice and extracted with ethyl acetate (100 mL×3). The combined organic layers were washed with brine and water, dried over anhydrous Na2SO4, and concentrated under vacuum to afford 3-bromo-5-hydroxybenzoic acid (3.8 g, 78% yield), which was directly used in next step. 1H NMR (400 MHz, d-DMSO) δ 10.27 (s, 1H), 7.43 (t, J=1.6 Hz, 1H), 7.28 (dd, J=1.2, 2.0 Hz, 1H), 7.15 (t, J=2.0 Hz, 1H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 30 minutes
  3. additionThe resulting mixture was poured
  4. custominto crushed ice
  5. extractionextracted with ethyl acetate (100 mL×3)
  6. washThe combined organic layers were washed with brine and water
  7. dry with materialdried over anhydrous Na2SO4
  8. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-3304d5b8b63b4eb9bdde214dacaba30f
Source dataset
uspto-grants-2011_06
Patent number
US07956052B2

Reaction notes

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