Phosphorus oxychloride → 2,9-Dichloro-1,10-phenanthroline

Participants

Reaction Steps

Under a stream of argon, to compound (5) (4.26 g; 17.4 mmol), phosphorus oxychloride (39 mL) and phosphorus pentachloride (4.48 g; 21.8 mmol) were added in an ice bath. The resulting reaction mixture was stirred and refluxed for 7 hours, and then evaporated under reduced pressure to remove phosphorus oxychloride. To the resulting residue, ice water and concentrated aqueous ammonia were added and the resulting reaction mixture was made alkaline. The solids which precipitated out were separated by filtration and washed with water, and then dried under reduced pressure to give 4.06 g (yield: 94%) of the title compound (6).

Provenance & Evidence