Phenacyl bromide → 4-Phenyl-1,3-oxazole

Participants

Reaction Steps

A solution of phenacyl bromide (4 g, 20.1 mmol) and ammonium formate (4.4 g, 70.35 mmol) in formic acid (20 mL) was refluxed for 5 h. The deep red mixture was cooled to r.t., diluted with water and basified with dilute sodium hydroxide solution. This was extracted with ethyl acetate (×3), then the combined organic layers were washed with water and brine, dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (60-120 mesh), eluting with 20% ethyl acetate-petroleum ether, to afford 4-phenyloxazole (1 g, 34%) as a pale yellow oil which solidifies at −20° C.

Provenance & Evidence