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

HRID 1171001Notes

Reaction equation

HRID 1171001 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, 1 H), 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-8a06f31c9f474bfbb409e73430b5b876
Source dataset
uspto-grants-2010_11
Patent number
US07829552B2

Reaction notes

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