Ethyl oxoacetate → 6,7-Dimethoxyquinoxalin-2-ol

HRID 255324Notes

Reaction equation

HRID 255324 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[C:7]([N+:9]([O-])=O)[C:6]([N+:12]([O-])=O)=[CH:5][C:4]=1[O:15][CH3:16].[O:17]=[CH:18][C:19](OCC)=O>C(O)C.C(O)(=O)C.[Pd]>[CH3:1][O:2][C:3]1[CH:8]=[C:7]2[C:6](=[CH:5][C:4]=1[O:15][CH3:16])[NH:12][C:18](=[O:17])[CH:19]=[N:9]2

Participants

5

Reactant 2

HCID 70211Ethyl oxoacetateHCID 2229891,2-Dimethoxy-4,5-dinitrobenzene

Product 1

HCID 113332106,7-Dimethoxyquinoxalin-2-olYield 38.8%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 18476134Acetic acid ethanolSolvent

Procedure

A mixture of 1,2-dimethoxy-4,5-dinitrobenzene (5.7 g, 25.0 mmol) in ethanol/acetic acid (140 mL, 1:1) was hydrogenated over palladium on carbon (10%, 1 g) at normal pressure and room temperature for 3 hours, then filtered through a pad of celite. The filtrate containing the crude diamine was treated with ethyl oxoacetate (50 wt % in toluene, 10 mL, 50 mmol) and the reaction was stirred at room temperature overnight. The resulting precipitate was collected by filtration. This material was suspended in a mixture of methanol/dichloromethane and solvent was removed under reduced pressure to remove traces of acetic acid to give 2.0 g (38%) of product as a solid.

Workup

  1. filtrationfiltered through a pad of celite
  2. additionThe filtrate containing the crude diamine
  3. filtrationThe resulting precipitate was collected by filtration
  4. additionThis material was suspended in a mixture of methanol/dichloromethane and solvent
  5. customwas removed under reduced pressure
  6. customto remove traces of acetic acid

Sources & evidence

ORD record
ord-db5b4f65ef05466496b3d77ab48bf680
Source dataset
uspto-grants-2011_01
Patent number
US07875715B2

Reaction notes

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