Sodium Hydroxide → 2-Chloro-5,6,7,8-tetrahydroquinolin-5-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of 7,8-dihydroquinoline-2,5(1H,6H)-dione (1.5 g, 9.19 mmol) in acetonitrile (22 mL) was added dropwise phosphorous oxychloride (1.714 mL, 18.39 mmol). The resulting solution was heated to 100° C. and stirred for 2 h. The reaction was cooled to RT and poured into ice-cold water. After basifying the mixture with 2 M sodium hydroxide solution it was extracted with ethyl acetate (3×). After each extraction the pH of the aqueous phase was checked and if necessary adjusted by adding 1 M sodium hydroxide solution. The combined organic layers were dried over sodium sulfate, filtered, and evaporated to dryness. The crude was purified by flash chromatography (silica gel, cyclohexane/ethyl acetate) yielding a colourless solid. Amount 1.23 g. Yield 74%.

Provenance & Evidence