text: Hexamethylenetetramine was discovered by Aleksandr Butlerov in 1859.
  It is prepared industrially by combining formaldehyde and ammonia:
  The reaction can be conducted in gas phase and in solution.
  The molecule has a tetrahedral cage-like structure, similar to adamantane. Four vertices are occupied by nitrogen atoms, which are linked by methylene groups. 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 ().