2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 8-chloro-3-ethylquinoxalin-2(1H)-one

HRID 75371Notes

Reaction equation

HRID 75371 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:11]=1[NH:10][C:9](=[O:12])[CH:8]([CH2:13][CH3:14])[NH:7]2.C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N.[OH-].[Na+]>O1CCOCC1.C([O-])(O)=O.[Na+].O>[Cl:1][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:11]=1[NH:10][C:9](=[O:12])[C:8]([CH2:13][CH3:14])=[N:7]2

Participants

7

Reactant 3

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinone2×HCID 14798Sodium HydroxideHCID 846214318-chloro-3-ethyl-3,4-dihydroquinoxalin-2(1H)-one

Product 1

HCID 866985098-chloro-3-ethylquinoxalin-2(1H)-oneYield 77.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 312751,4-DioxaneSolventHCID 516892Sodium BicarbonateSolvent

Procedure

To a solution of 8-chloro-3-ethyl-3,4-dihydroquinoxalin-2(1H)-one (1.30 Kg, 6.17 mol) in anhydrous 1,4-dioxane (15 L) was added DDQ (1.47 Kg, 6.48 mol). The reaction mixture was stirred for 3 h (the internal temperature went up to 45° C. after DDQ addition). After this time LC-MS analysis showed that the reaction was complete. The mixture was evaporated under reduced pressure to give a brown residue. To this residue was added 2M aqueous NaOH to adjust the pH to 7-8. The resulting yellow solid was collected by filtration, suspended in saturated aq. NaHCO3, stirred for 1 h, and filtered to give a light green solid. The light green solid was suspended in saturated aqueous NaHCO3, stirred, filtered and washed with saturated aqueous NaHCO3 and water to give an off-white solid. The off-white solid was suspended in water, mixed well, filtered, washed with water, air-dried overnight, and dried under high vacuum at 50° C. to give 8-chloro-3-ethylquinoxalin-2(1H)-one (1 Kg). 1H NMR (DMSO-d6) δ ppm 7.69-7.75 (m, 1H), 7.59-7.65 (m, 1H), 7.29 (t, J=8.0 Hz, 1H), 2.84 (q, J=7.4 Hz, 2H), 1.23 (t, J=7.4 Hz, 3H). Mass Spectrum (ESI) m/z=209.1 (M+1).

Workup

  1. customwent up to 45° C.
  2. customThe mixture was evaporated under reduced pressure
  3. customto give a brown residue
  4. filtrationThe resulting yellow solid was collected by filtration
  5. stirringstirred for 1 h
  6. filtrationfiltered
  7. customto give a light green solid
  8. stirringstirred
  9. filtrationfiltered
  10. washwashed with saturated aqueous NaHCO3 and water
  11. customto give an off-white solid
  12. additionmixed well
  13. filtrationfiltered
  14. washwashed with water
  15. customair-dried overnight
  16. customdried under high vacuum at 50° C.

Sources & evidence

ORD record
ord-510aa5b37f2e4f83956770aa475385cc
Source dataset
uspto-grants-2014_09
Patent number
US08835432B2

Reaction notes

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