Glyoxal → 6-Bromoquinoxaline

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).

1. temperatureThe resulting mixture was refluxed for 10 hours
2. concentrationThe mixture was concentrated in vacuo
3. additionthe residue was diluted in 100 mL of EtOAc
4. washThe organic solution was washed with 40 mL of satd
5. dry with materialNaHCO3 and 40 mL of brine, dried over Na2SO4
6. concentrationconcentrated in vacuo
7. customThe residue was purified by a silca gel column chromatography (5% EtOAc/hex to EtOAC)

ORD record

ord-628e10b5687742e7969cc9b392980838

Source dataset

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08212041B2