Sodium Iodide → 6-Bromo-1,2,3,4-tetrahydroquinoxalin-2-one

HRID 2358966Notes

Reaction equation

HRID 2358966 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([Br:8])[CH:5]=[CH:4][C:3]=1[NH:9][C:10](=[O:13])[CH2:11]Cl.[I-].[Na+].C(=O)([O-])[O-].[Na+].[Na+]>C(#N)C>[Br:8][C:6]1[CH:7]=[C:2]2[C:3](=[CH:4][CH:5]=1)[NH:9][C:10](=[O:13])[CH2:11][NH:1]2

Participants

5

Reactant 3

HCID 5238Sodium IodideHCID 10340Sodium CarbonateHCID 66911433N-(2-Amino-4-bromophenyl)-2-chloroacetamide

Product 1

HCID 669113076-Bromo-1,2,3,4-tetrahydroquinoxalin-2-oneYield 34.1%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of N-(2-amino-4-bromophenyl)-2-chloroacetamide (4.5 g, 17.0 mmol), sodium iodide (101 mg, 2.0 mmol) and sodium carbonate (3.6 g, 33.8 mmol) in 300 ml acetonitrile was refluxed overnight under an atmosphere of nitrogen. Then the acetonitrile was removed under vacuum. The resulting solid was suspended in 150 ml water acidified to pH 5-6 with 1 N HCl. Extraction with ethyl acetate, washing of the combined organic layers with brine, drying over MgSO4, removing the solvent under reduced pressure and purification of the crude product by flash chromatography on silica gel (petroleum ether/ethyl acetate, 1.5/1) yielded 6-bromo-3,4-dihydroquinoxalin-2(1H)-one (1.3 g, 5.8 mmol, 34%) as yellow solid.

Workup

  1. temperaturewas refluxed overnight under an atmosphere of nitrogen
  2. customThen the acetonitrile was removed under vacuum
  3. extractionExtraction with ethyl acetate
  4. washwashing of the combined organic layers with brine
  5. dry with materialdrying over MgSO4
  6. customremoving the solvent
  7. customunder reduced pressure and purification of the crude product by flash chromatography on silica gel (petroleum ether/ethyl acetate, 1.5/1)

Sources & evidence

ORD record
ord-7d2690bd66654f5d9754c1f6d1021483
Source dataset
uspto-grants-2014_04
Patent number
US08685960B2

Reaction notes

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