Sodium Dithionite → 2-Amino-6-bromophenol

HRID 842103Notes

Reaction equation

HRID 842103 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([N+:8]([O-])=O)[C:3]=1[OH:11].S(S([O-])=O)([O-])=O.[Na+].[Na+].NC1C(O)=C(Br)C=C(Br)C=1>C(O)C.O.O>[NH2:8][C:4]1[C:3]([OH:11])=[C:2]([Br:1])[CH:7]=[CH:6][CH:5]=1

Participants

6

Reactant 3

HCID 24489Sodium DithioniteHCID 3518632-amino-4,6-dibromophenolHCID 135454532-Bromo-6-nitrophenol

Product 1

HCID 155315062-Amino-6-bromophenol

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 19096565Water ethanolSolvent

Procedure

2-Bromo-6-nitrophenol (1.506 g, 0.0057 mol, containing 2,4-di-bromo-6-nitrophenol, 18% w/w) and sodium hydrosulfite (3.05 g, 85%, 0.015 mol) were heated at reflux in ethanol/water (50 ml of a 5:1 v/v mixture). After 2 hours, the reaction mixture was diluted with water (150 ml) and extracted with dichloromethane (3×50 ml), and ethyl acetate (100 ml). The organic extracts were combined, dried over calcium sulfate, evaporated in vacuo, and purified by flash chromatography (SiO2, petrol/ether 1:1 v/v) to furnish a mixture of the title compound and 6-amino-2,4-di-bromophenol (0.600 g, of a 76:24 w/w mixture as judged by 1 H-NMR). Yield 6-amino-2-bromophenol, 43%.

Workup

  1. extractionextracted with dichloromethane (3×50 ml), and ethyl acetate (100 ml)
  2. dry with materialdried over calcium sulfate
  3. customevaporated in vacuo
  4. custompurified by flash chromatography (SiO2, petrol/ether 1:1 v/v)
  5. customto furnish

Sources & evidence

ORD record
ord-fff0886d54ee4f849e8141f952d030c2
Source dataset
uspto-grants-2002_04
Patent number
US06372770B1

Reaction notes

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