Reaktion #71394

Reaktionsgleichung

SelectFluor

5-bromo-8-(3,5-dimethoxy-phenyl)-quinoxaline

→

5-bromo-8-(2-fluoro-3,5-dimethoxy-phenyl)-quinoxaline

Lösungsmittel

CH3CN

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigequenched by addition of H2O
2. 2
   Einengenconcentrated
3. 3
   Sonstigeto remove CH3CN
4. 4
   workup.ADDITIONThe resulting mixture was diluted with EtOAc/H2O
5. 5
   Filtrationfiltered
6. 6
   Sonstigeto provide a white solid (batch 1)
7. 7
   ExtraktionThe filtrate was extracted with EtOAc
8. 8
   WaschenThe organic phase was washed with H2O and brine
9. 9
   Trocknendried (Na2SO4)
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated
12. 12
    Sonstigeto afford batch 2
13. 13
    Sonstigepurified by silica gel MPLC (Hex/EtOAc, 7:3)

Vorschrift

SelectFluor (20.5 g, 58 mmol, 2 equiv) was added portionwise to a solution of 5-bromo-8-(3,5-dimethoxy-phenyl)-quinoxaline (Step 1.4) (10 g, 29 mmol) in CH3CN (300 mL) at rt. The reaction mixture was stirred at rt for 0.5 h, quenched by addition of H2O and concentrated to remove CH3CN. The resulting mixture was diluted with EtOAc/H2O and filtered to provide a white solid (batch 1). The filtrate was extracted with EtOAc. The organic phase was washed with H2O and brine, dried (Na2SO4), filtered and concentrated to afford batch 2. The two batches were combined and purified by silica gel MPLC (Hex/EtOAc, 7:3) to afford a sample of 5-bromo-8-(2-fluoro-3,5-dimethoxy-phenyl)-quinoxaline (Step 94.3) and a sample of the title compound which was further purified by trituration in EtOAc to provide 2.28 g of a white solid. Title compound: ESI-MS: 381.0/382.9 [M+H]+; tR=4.92 min (System 1); TLC: Rf=0.26 (Hex/EtOAc, 7:3).

Quelle