Dichloromethane → 4-chloro-2-(2,6-dimethylphenyl)-6-(5-isopropyl-2-methylphenyl)-7,8-dihydro-1,6-naphthyridin-5(6H)-one

Participants

Reaction Steps

To a solution of crude 2-(2,6-dimethylphenyl)-4-hydroxy-6-(5-isopropyl-2-methylphenyl)-7,8-dihydro-1,6-naphthyridin-5(6H)-one (1.4 g, 3.50 mmol) in DCM (35.0 mL) was added Vilsmeier's reagent (0.895 g, 6.99 mmol) as a solid in one portion and the reaction mixture stirred at room temperature. After 2 h 500 mg of Vilsmeier's reagent was added and stirring continued. After 35 min an additional portion of 200 mg of Vilsmeier's reagent was added and stirring continued. After 15 min the reaction mixture was diluted with DCM and poured into saturated aqueous sodium bicarbonate solution containing 1 N NaOH. The layers were separated and the aqueous layer was extracted with DCM (2×). The combined organic layers were dried over sodium sulfate, filtered, and concentrated. The residue was purified by FCC (0-20% EtOAc/heptane) to provide 4-chloro-2-(2,6-dimethylphenyl)-6-(5-isopropyl-2-methylphenyl)-7,8-dihydro-1,6-naphthyridin-5(6H)-one. MS (ESI+) m/z 419.2 (M+H)+.

Provenance & Evidence