Synthesis
3-Bromo-5-chloropyridone (8.0 g, 38.4 mmole) was dissolved in dimethylformamide (60 ml) at ambient temperature. Phosphorus (V) tribromide oxide (16.5 g, 57.6 mmoles) was added and the reaction heated to 80° C for 72 hours. After cooling, the reaction was poured onto 800 g of ice. Vacuum filtration provided the product as a dark solid (6.85 g). Hexane (225 ml) and decolorizing carbon was added to the crude product and the contents heated to reflux and then filtered through celite. The clear colorless filtrate was stripped under vacuum to yield 2,3-Dibromo-5-chloropyridine as a white solid (5.3 g, 51%).
