Methylglyoxal → 2-Methyl-5-nitroquinoxaline

HRID 1883184Notes

Reaction equation

HRID 1883184 reaction equation
[N+:1]([C:4]1[C:5]([NH2:11])=[C:6]([NH2:10])[CH:7]=[CH:8][CH:9]=1)([O-:3])=[O:2].[OH-].[K+].[CH3:14][C:15]([CH:17]=O)=O.O>C(O)C>[CH3:17][C:15]1[CH:14]=[N:11][C:5]2[C:6](=[CH:7][CH:8]=[CH:9][C:4]=2[N+:1]([O-:3])=[O:2])[N:10]=1

Participants

6

Reactant 4

HCID 880MethylglyoxalHCID 962WaterHCID 14797Potassium HydroxideHCID 43595253-Nitro-1,2-phenylenediamine

Product 1

HCID 235103262-Methyl-5-nitroquinoxalineYield 67%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 3-nitro-1,2-phenylenediamine (2.67 g) and a 2N KOH (8.7 mL) in ethanol (250 mL) was added a 40% aqueous solution of pyruvic aldehyde (17.72 g) at 60° C. The mixture was heated under reflux for 10 minutes, and thereto was added water (150 mL). The mixture was cooled to room temperature, and concentrated under reduced pressure. The precipitated crystals were collected by filtration, washed with cold water, and dried under reduced pressure to give 2-methyl-5-nitroquinoxaline (2.21 g, 67%) as pale brown solid.

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux for 10 minutes
  3. concentrationconcentrated under reduced pressure
  4. filtrationThe precipitated crystals were collected by filtration
  5. washwashed with cold water
  6. customdried under reduced pressure

Sources & evidence

ORD record
ord-22a5b492d44f4d2ebe31a4a67d487709
Source dataset
uspto-grants-2004_07
Patent number
US06759429B2

Reaction notes

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