How is 5-Bromo-3,4-pyridinediamine (CAS: 4635-08-9) typically synthesized?

5-Bromo-3,4-pyridinediamine is typically synthesized through a nucleophilic aromatic substitution reaction, where 3,4-pyridinediamine reacts with bromine in the presence of a base such as sodium hydroxide. The reaction is carried out in a polar aprotic solvent like dimethylformamide (DMF). The yield and selectivity of the reaction can be enhanced through optimization of the reaction conditions.