Glyoxal → 6-Bromoquinoxaline

Reaktionsgleichung

[Br:1][C:2]1[CH:3]=[C:4]([NH2:9])[C:5]([NH2:8])=[CH:6][CH:7]=1.[CH:10](=O)[CH:11]=O>CCO.O>[Br:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:6][CH:7]=1)[N:8]=[CH:11][CH:10]=[N:9]2

Komponenten

Versuchsvorschrift

To a solution of 4-bromobenzene-1,2-diamine (4.0 g, 21 mmol) in 60 mL of EtOH was added 40% glyoxal aldehyde (4.1 ml, 32 mmol) solution in water. The resulting mixture was refluxed for 10 hours. The mixture was concentrated in vacuo and the residue was diluted in 100 mL of EtOAc. The organic solution was washed with 40 mL of satd. NaHCO3 and 40 mL of brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by a silca gel column chromatography (5% EtOAc/hex to EtOAC) to give light yellow solid 6-bromoquinoxaline. MS (ESI, pos. ion) m/z: 208.9 (M+1).