Phosphoryl bromide, also known as phosphorus oxybromide, is an inorganic compound with the formula POBr3. It can be prepared via the slow addition of liquid bromine to phosphorus tribromide at 0 °C, followed by the slow addition of water and vacuum distillation of the resulting slurry. It is prepared according to the equation: 3 PBr5 + P2O5 → 5 POBr3