Phosphorus oxychloride → 2-Chloro-7,8-dihydro-1,6-naphthyridin-5(6H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-hydroxy-7,8-dihydro-6H-[1,6]naphthyridin-5-one (17 g, 73.1 mmol) in phosphorus oxychloride (30 mL) was stirred at 100° C. for 8 h. The solvent was evaporated in vacuo. The mixture was basified with a saturated solution of NaHCO3 and extracted with EtOAc. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; petroleum ether/EtOAc 1/1). The desired fractions were collected and the solvents evaporated in vacuo to yield 2-chloro-7,8-dihydro-1,6-naphthyridin-5(6H)-one (4.81 g, 36%) as a solid.

Provenance & Evidence