How is 2-Bromo-3-chloro-5-nitropyridine (CAS: 22353-41-9) typically synthesized?

2-Bromo-3-chloro-5-nitropyridine (CAS: 22353-41-9) is synthesized through the bromination of 3-chloro-5-nitropyridine using bromine in the presence of a Lewis acid catalyst such as aluminum trichloride. The reaction is conducted in an inert solvent like dichloromethane. The yield is around 85-90%, and the procedure is selective for the bromination of the 2-position. This method is widely used in the synthesis of functionalized pyridines for various applications.