Thionyl bromide is primarily used in organic synthesis as a brominating agent. It is particularly effective in converting alcohols to alkyl bromides, a process that is crucial in the preparation of various organic compounds. Additionally, it serves as a reagent in the synthesis of pharmaceuticals and agrochemicals, where precise bromination is required. Its ability to introduce bromine atoms into molecules makes it valuable in the production of specialty chemicals and intermediates. In some cases, it is also employed in the preparation of brominated polymers, which are used in flame retardants and other industrial applications. It is a highly reactive compound and should be handled with care due to its corrosive and toxic nature.