Phosphorus oxychloride → HCID 86662009, compound

Participants

Reaction Steps

A solution of 7-methylsulfanyl-1H-quinoxalin-2-one (9.23 g, 48.0 mmol, 1.0 eq) in phosphorus oxychloride (36 mL, 384.0 mmol, 8.0 eq) is heated under reflux for 30 minutes. Then the reaction mixture is cooled down to room temperature and the solvent is evaporated. The residue is poured into ice water, the resulting mixture is basified with saturated sodium hydrogen carbonate to pH=8=9 and extracted with ethyl acetate (3×50 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give a crude product that is purified by column chromatography (silica gel, eluent: petroleum ether:dichloromethane, 4:1 to 1:1, v/v) to afford 2-chloro-7-methylsulfanyl-quinoxaline as a green solid (3.41 g, 33% yield).

Provenance & Evidence