A 250 mL RBF equipped with an addition funnel is set up and 16 g of potassium chlorate is added to the flask, then a slow addition of 50 g of phosphorus trichloride is started. Small explosions or flames may occur while the addition hence the apparatus should be flushed with nitrogen gas. After the addition, the solution is distilled in an oil bath and everything which comes off before 100°C is discarded, the receiver should be protected with a drying tube. The distillate should be redistilled to obtain high purity product.
3PCl3 + KCIO3 = KCI + 3POCl3