Ammonia → 4-Bromo-1,8-naphthyridine

Participants

Reaction Steps

To a solution of 1,8-naphthyridin-4-ol (59 g, 400 mmol) in acetonitrile (500 ml) was added phosphorus oxide tribromide. The reaction mixture was heated to reflux. After 1 hour, the reaction mixture was carefully diluted with ice and the resulting solution was basified with ammonia solution (25%) to pH>7. The reaction mixture was partially concentrated in vacuo, then extracted with chloroform (4×500 ml). The organics were dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether gradient) to afford 4-bromo-1,8-naphthyridine.

Provenance & Evidence