Hexamethylenetetramine
Hexamethylenetetramine or methenamine is a heterocyclic organic compound with the formula (CH2)6N4. This white crystalline compound is highly soluble in water and polar organic solvents. It has a cage-like structure similar to adamantane. It is useful in the synthesis of other chemical compounds, e.g., plastics, pharmaceuticals, rubber additives. It sublimes in vacuum at 280 °C.
Synthesis, structure, reactivity
The compound was discovered by Aleksandr Butlerov in 1859.
Hexamethylenetetramine is prepared industrially by combining formaldehyde and ammonia. The reaction can be conducted in gas phase and in solution.
The molecule has a symmetric tetrahedral cage-like structure, similar to adamantane, whose four "corners" are nitrogen atoms and "edges" are methylene bridges. Although the molecular shape defines a cage, no void space is available at the interior for binding other atoms or molecules, unlike crown ethers or larger cryptand structures.
The molecule behaves like an amine base, undergoing protonation and N-alkylation.