Dimethylamine → [3-(Dimethylamino)propyl](triphenyl)phosphanium bromide

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 3-bromopropyltriphenylphosphonium bromide (Olo-IM3) (420 g, 0.90 mol) in absolute ethanol (664 g) a solution of dimethylamine in absolute ethanol (368 g, 2.69 mol, assay: 33%) was added slowly within 30 minutes at room temperature. After complete addition the suspension was stirred 1 hour at reflux whereupon a solution was obtained. The solution was cooled to a temperature of 0-10° C. and acetyl bromide (202.7 g, 1.65 mol) was added dropwise until the pH was ≦1, and the resulting suspension was allowed to warm to 20-25° C. After the white suspension was filtered the wet product washed with absolute ethanol (237 g) and then dried under vacuum (15 h, 70° C.) to give 3-dimethylaminopropyltriphenylphosphonium bromide*HBr (Olo-IM4) as a white solid (yield: 471.2 g, 0.77 mol, 85.1%; HPLC assay: 83.2%, HPLC purity: 98.72%).

Provenance & Evidence