2,6-Diaminopyridine
2,6-Diaminopyridine is an intermediate and coupling agent for hair dyes. 2,6-Diaminopyridine participates in organic synthesis reactions such as N-methylation and can bind metal ions by forming macrocyclic ligands through condensation with aldehydes. 2,6-Diaminopyridine can be used to synthesize the analgesic phenazopyridine hydrochloride (HY-B0985).