Ammeline Explained

Ammeline (4,6-diamino-2-hydroxy-1,3,5-triazine) is a triazine derivative. It is the hydrolysis product of melamine.^[1]

Synthesis

Ammeline can be synthesized by the pyrolysis of urea or the condensation reaction among 2 moles of dicyandiamide and 1 mole of biuret.

2 C₂H₄N₄ + C₂H₅N₃O₂ → 2C₃H₅N₅O + NH₃

Chemical properties

Ammeline is weakly acidic with pKa ~9. It can form nitrate, sulfate, chromate, and oxalate salts. Ammeline reacts with boiling dilute hydrochloric acid to form melem and ammonia.

Ammeline is the first step in melamine hydrolysis. Further hydrolysis (e.g. boiling ammeline with dilute alkali) yields ammelide.

Notes and References

1. B. Bann and S.A. Miller . Melamines and derivatives of melamine . . 10.1021/cr50019a004 . 58 . 131–172 . 1958.