5-Acetyl-8-(benzyloxy)-1,2-dihydroquinolin-2-one → 8-Benzyloxy-5-(2-bromoacetyl)-2-hydroxyquinoline

Participants

Reaction Steps

To a suspension of 5-acetyl-8-(benzyloxy)quinolin-2(1H)-one (19.4 g, 66.4 mmol) in anhydrous THF (240 mL) and anhydrous methanol (165 mL), a solution of tetra-n-butylammonium tribromide (54.5 g, 113.0 mmol) in anhydrous THF (130 mL) was added dropwise over 1.5 hours. The resultant solution was stirred at RT overnight before concentrating under reduced pressure without heating. The residue was re-dissolved in methanol (200 mL). Saturated aqueous ammonium chloride solution (390 mL) was added with ice-cooling. The resultant suspension was filtered, and the solid was washed with water and dried under vacuum. The solid was suspended in dichloromethane and methanol (1:1 v/v, 100 mL) for 90 minutes. The solid was collected by filtration, washed with dichloromethane and air-dried to afford the title compound (18.0 g, 73%).

Provenance & Evidence