Phosphorus oxychloride → HCID 89782123, compound

Participants

Reaction Steps

A solution of 8-bromo-3-(trifluoromethyl)quinoxalin-2(1H)-one (432.0 mg, 1.474 mmol) in POCl3 (5.0 mL) was heated at reflux for 10 h then at 100° C. for 2.5 d, then at 140° C. for 10 h. Excess POCl3 was removed in vacuo, and the residue was taken up in DCM (60 mL) and transferred to an Erlenmeyer flask before saturated aq. NaHCO3 (40 mL) was added cautiously (over 5 min) with rapid stirring. The resulting biphasic mixture was stirred rapidly for 5 min (some gas evolution), and the organic layer was separated. The aq. layer was extracted with DCM (3×20 mL), and all organic layers were combined, dried over Na2SO4, filtered, and concentrated in vacuo to provide 5-bromo-3-chloro-2-(trifluoromethyl)quinoxaline (224c, 52%). MS (ESI, pos. ion) m/z: 310.9 (M+1).

Provenance & Evidence