Tetrabutylammonium bromide is prepared buy mixing n-butylbromide with tributylamine in acetonitrile, in an inert atmosphere,
under reflux conditions for a sufficient period of time to form a solution containing tetrabutylammonium bromide,
Tetrabutylammonium bromide (TBAB) is a quaternary ammonium salt with a bromide commonly used as a phase transfer catalyst. It is used to prepare many other tetrabutylammonium salts by salt metathesis reactions.