Glyoxal → 6-Methylquinoxaline

HRID 2236074Notes

Reaction equation

HRID 2236074 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH3:9])[CH:5]=[CH:6][C:7]=1[NH2:8].[CH:10](S(O)(=O)=O)(O)[CH:11](S(O)(=O)=O)O.C(C=O)=O>O>[CH3:9][C:4]1[CH:3]=[C:2]2[C:7](=[CH:6][CH:5]=1)[N:8]=[CH:11][CH:10]=[N:1]2

Participants

5

Reactant 3

HCID 7860GlyoxalHCID 103323,4-DiaminotolueneHCID 101737Glyoxal bisulfite

Product 1

HCID 2425676-MethylquinoxalineYield 77.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
60 °C

Procedure

A solution of 3,4-diaminotoluene (Aldrich, 100 g, 0.82 mol) in 600 mL of hot water (temp. 70-75° C.) was added rapidly to a 60° C. slurry of glyoxal-sodium bisulfite adduct (Aldrich, 239.5 g, 0.9 mol, 1.1 eq) in 400 mL of water. The resulting dark-brown clear solution was heated at 60° C. for 1 hr, then 5 g (0.02 mol) of additional glyoxal adduct was added. The mixture was allowed to cool to r.t. and filtered through a paper filter. The filtrate was neutralized with 5 M aq. NaOH to pH 7.5-7.8 and then extracted with ether (4×400 mL). The extract was dried over Na2SO4 and concentrated on a rotary evaporator to afford 92 g of brown oil which was distilled in vacuum (bp. 100-102° C. at 10 mm Hg; Cavagnol, J. C.; Wiselogle, F. Y. J. Am. Chem. Soc. 1947, 69, 795; 86° C. at 1 mm Hg). Yield 89 g (75%) as a pale-yellow oil.

Workup

  1. temperatureto cool to r.t.
  2. filtrationfiltered through a paper
  3. filtrationfilter
  4. extractionextracted with ether (4×400 mL)
  5. dry with materialThe extract was dried over Na2SO4
  6. concentrationconcentrated on a rotary evaporator

Sources & evidence

ORD record
ord-00a5643ecf4e47d0a7fdcfb8fd989ff5
Source dataset
uspto-grants-2010_05
Patent number
US07714130B2

Reaction notes

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