Oxygen → 6,7-Dichloro-2,3-dimethoxy-5-formylquinoxaline

Participants

Reaction Steps

A mixture of ozone and oxygen was bubbled gently through a stirred solution of 6,7-dichloro-2,3-dimethoxy-5-ethenylquinoxaline (1.76 g, 6.2 mmol) in chloroform (200 mL) at -60° C. until a blue colour persisted. The solution was purged with nitrogen, and then triphenylphosphine (3.23 g, 12.3 mmol) was added. The mixture was allowed to warm to room temperature and stirred for a further 16 hours. The chloroform was removed under reduced pressure and the residue purified by flash chromatography (eluting with toluene) to give 6,7-dichloro-2,3-dimethoxy-5-formylquinoxaline (1.60 g, 90%) as a fluffy white solid.

Provenance & Evidence