A convenient and economic way to produce anhydrous hydrogen bromide

Article abstract of DOI:10.1055/s-1994-25506

Bromide promoted decomposition of tert-butyl bromide in the presence of triphenylphosphine gives, besides isobutene, hydrogen(triphenyl)phosphonium bromide. When heated to approximately 150°C in the presence of xylene, the latter salt liberates hydrogen bromide which may then be trapped in an aprotic solvent such as diethyl ether.