Sodium Hydroxide → 8-Quinolinol, 5-benzyl-

Participants

Reaction Steps

To a solution of 2.88 g (72 mmol, 5.5 eq.) of powdered sodium hydroxide and 6.55 ml (135 mmol, 10.3 eq.) of hydrazine monohydrate in 40 ml of ethylene glycol was added 3.08 g (13.1 mmol) of 5-benzoyl-8-quinolinol and the resultant mixture was heated at 120° C. for one hour. The reflux condenser was removed and heating was continued until the pot temperature had reached 195° C. The condenser was replaced and refluxing continued for an additional three hours. The solution was cooled, diluted with 120 ml of water and brought to pH 7 with 1M hydrochloric acid. After the addition of 100 ml of pH 6.5 lM phosphate buffer and 500 ml of ethyl acetate, the layers were separated. The organic phase was washed with 100 ml of pH 6.5 1M phosphate buffer, two 100 ml portions of water and 100 ml of brine, dried over sodium sulfate and evaporated to yield 3.64 g of a dark brown, viscous oil. Purification required flash chromatography on 200 g of silica, eluted with 5:95 methanol:dichloromethane followed by recrystallization from heptane to provide 2.14 g of yellow crystals:melting point 112°-113° C.

Provenance & Evidence