4-Bromo-2-nitrophenol → 2-Amino-4-Bromophenol

HRID 2108642Notes

Reaction equation

HRID 2108642 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([OH:8])=[C:4]([N+:9]([O-])=O)[CH:3]=1.[O-]S(S([O-])=O)=O.[Na+].[Na+]>CO>[NH2:9][C:4]1[CH:3]=[C:2]([Br:1])[CH:7]=[CH:6][C:5]=1[OH:8]

Participants

4

Reactant 2

HCID 243644-Bromo-2-nitrophenolHCID 24489Sodium Dithionite

Product 1

HCID 3518402-Amino-4-BromophenolYield 75.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a stirring solution of 4-bromo-2-nitro-phenol (6 g, 27.52 mmol) in MeOH (150 mL) at room temperature was added a suspension of Na2S2O4 (29 g, 165.13 mmol). The mixture was stirred at room temperature for 3 hrs, filtered and concentrated down. The residue was partitioned between EtOAc and water. The organic layer was collected and dried over Na2SO4, filtered and concentrated under reduced pressure to afford crude 2-amino-4-bromo-phenol as a yellow solid (3.9 g, 75%): 1H NMR (200 MHz, DMSO-d6): δ 9.27 (s, 1H), 6.70 (d, J=2.2 Hz, 1 H), 6.50 (m, 2 H), 4.79 (s, 2 H); TLC conditions: Uniplate silica gel, 250 microns; Mobile phase=20% ethyl acetate in hexanes; Rf=0.35.

Workup

  1. filtrationfiltered
  2. concentrationconcentrated down
  3. customThe residue was partitioned between EtOAc and water
  4. customThe organic layer was collected
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-43c14b64fc8f4aa19ee74fe52bd16321
Source dataset
uspto-grants-2009_04
Patent number
US07514419B2

Reaction notes

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