In small-scale brominations, where it is much more convenient and agreeable to measure and use than elemental bromine.
Pyridinium Tribromide is a reagent used in the α-thiocyanation of ketones and has also been applied to the synthesis of β-adrenergic blocking agents (also known as β-blockers) for patients with heart
failure.
Pyridine hydrobromide perbromide is used as a brominating reagent in alfa-bromination and alfa-thiocyanation of ketones, phenols, unsaturated and aromatic ethers. It is used as a raw material in the preparation of beta-adrenergic blocking agents. Furthermore, it is used as an analytical reagent.
It is a very good brominating agent-liberating one mol of Br2. Purify it by recrystallisation from glacial acetic acid (33g from 100mL of AcOH) to give orange-red crystals. [Fieser & Fieser Reagents for Organic Chemistry 1 967 1967, Englert & McElvain J Am Chem Soc 51 865 1929, Beilstein 20 II 103, 20/5 V 181.]
