Selectfluor → 5-Bromo-8-(2-fluoro-3,5-dimethoxy-phenyl)-quinoxaline

Participants

Reaction Steps

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).

Provenance & Evidence