Bromide ion → Benzo(b)quinolizinium, bromide (1:1)

Participants

Reaction Steps

A mixture of 1526.8 g (4.74 mol) of 2-(1,3-dioxolan-2-yl)-1-benzylpyridinium bromide in 9 L of 48% HBr solution was heated on a steam-bath until the bromide dissolved. The mixture was heated (heating mantle) in vacuo (aspirator) to remove HBr solution. The dry residue was suspended in 800 mL of HBr solution, cooled, and 4 L of THF was slowly added. The reaction mixture was filtered to afford 1080 g (87%) of benzo[b]quinolizinium bromide as a green solid. Benzo[b]quinolizinium bromide (586 g) was dissolved in 2.4 L of hot water and filtered to remove an insoluble dark material. The filtrate was cooled in ice-water for 4 h, filtered, and the residue was washed with water, dried in vacuo at room temperature for 9 days to afford 508.8 g (86.8%) of benzo[b]quinolizinium bromide (Formula II: R1 =R2 =R7 =H; X- --=Br-).

Provenance & Evidence