Water → 5-Chloro-3,4-dihydroquinoxalin-2(1H)-one

HRID 558964Notes

Reaction equation

HRID 558964 reaction equation
C([N:5]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][C:13]=2[Cl:15])[NH:8][C:7](=[O:16])[CH2:6]1)(C)(C)C.[BH4-].[Na+].O>S(=O)(=O)(O)O>[Cl:15][C:13]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:14]=1[NH:5][CH2:6][C:7](=[O:16])[NH:8]2

Participants

5

Reactant 3

HCID 962WaterHCID 4311764Sodium borohydrideHCID 107763594-tert-Butyl-5-chloro-3,4-dihydro-1H-quinoxalin-2-one

Product 1

HCID 105593595-Chloro-3,4-dihydroquinoxalin-2(1H)-one

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

4-tert-Butyl-5-chloro-3,4-dihydro-1H-quinoxalin-2-one from Example 12C (1.5 g, 6.1 mmol) was suspended in 2N sulphuric acid (45 ml) and stirred for 18 h. The mixture was filtered and the filtrate was neutralised with sodium hydrogen carbonate, extracted with EtOAc, dried and evaporated. The residue was taken up in ethanol (30 ml) and cooled in an ice/water bath. Sodium borohydride (460 mg, 12 mmol) was added and the mixture was allowed to warm to room temperature over 2 h. Water (1 ml) was added and the mixture was evaporated. The residue was triturated with ice-cold water, filtered, washed with ice-cold water and dried in vacuo over phosphorous pentoxide to give an orange solid; yield 550 mg, 49%.

Workup

  1. filtrationThe mixture was filtered
  2. extractionextracted with EtOAc
  3. customdried
  4. customevaporated
  5. temperaturecooled in an ice/water bath
  6. customthe mixture was evaporated
  7. customThe residue was triturated with ice-cold water
  8. filtrationfiltered
  9. washwashed with ice-cold water
  10. dry with materialdried in vacuo over phosphorous pentoxide
  11. customto give an orange solid

Sources & evidence

ORD record
ord-54f57c16c2534a318d0c0f1572f3d10a
Source dataset
uspto-grants-2011_11
Patent number
US08063038B2

Reaction notes

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