Hydrogen Bromide → 5-Bromoquinoline

Participants

Reaction Conditions

Reaction Steps

Sodium nitrite (2.5 g, 41.8 mmol) was dissolved in 15 mL water. Copper (I) bromide (6.0 g, 41.8 mmol) was dissolved in 38 mL of 48% HBr and heated to 75° C. The 5-aminoquinoline (5.0 g, 34.7 mmol) was suspended in 15 mL water and 18 mL 48% HBr and cooled to 0° C. The sodium nitrite solution was added to the 5-aminoquinoline solution at 0° C. The resulting diazonium solution was added slowly to the warmed CuBr solution. The reaction mixture was stirred at room temperature for 2 hr. The reaction mixture was basified with sodium hydroxide, then filtered through celite. The solid was washed with methylene chloride, and the aqueous material was extracted with methylene chloride. The organic layers were combined, dried with Na2SO4, and concentrated in vacuo. The crude product was chromatographed with 2:1 hexane/ethyl acetate to yield 5.7 g (80%) of 5-bromo-quinoline as a yellow oil. MS (APCI) m/z 208.0 (M+1).

Provenance & Evidence