Sodium Dithionite → 2-Amino-4-bromo-5-fluorophenol

HRID 1668352Notes

Reaction equation

HRID 1668352 reaction equation
[O-]S(S([O-])=O)=O.[Na+].[Na+].[Br:9][C:10]1[C:15]([F:16])=[CH:14][C:13]([OH:17])=[C:12]([N+:18]([O-])=O)[CH:11]=1>O.C(O)C>[NH2:18][C:12]1[CH:11]=[C:10]([Br:9])[C:15]([F:16])=[CH:14][C:13]=1[OH:17]

Participants

5

Reactant 2

HCID 24489Sodium DithioniteHCID 547590604-Bromo-5-fluoro-2-nitrophenol

Product 1

HCID 383722992-Amino-4-bromo-5-fluorophenol

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A suspension of Na2S2O4 (51.6 g, 296 mmol) in water (122 mL) was added slowly to a refluxed mixture of 4-bromo-5-fluoro-2-nitrophenol (14 g, 59.3 mmol) in ethanol (1000 mL). The resulting mixture was refluxed for 1 h. After cooling down the salts were filtered off and the filtrate was partially concentrated. Brine was added, extracted with diethyl ether, the extract dried and concentrated to give the crude title compound which was used without further purification (9.2 g, 75%). 1H-NMR (400 MHz, DMSO) 4.65 (br, 2H), 6.60 (d, J=11.3, 1H), 6.76 (d, J=7.8, 1H), 9.80 (br, 1H).

Workup

  1. temperatureThe resulting mixture was refluxed for 1 h
  2. temperatureAfter cooling down the salts
  3. filtrationwere filtered off
  4. concentrationthe filtrate was partially concentrated
  5. additionBrine was added
  6. extractionextracted with diethyl ether
  7. customthe extract dried
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-bcab26d2617248f698acdfe409a66792
Source dataset
uspto-grants-2011_08
Patent number
US07989442B2

Reaction notes

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