Production method of pyrazine

Pyrazines and their derivatives can be synthesized by a variety of methods. Commercially, ethanolamine is synthesized by dehydrogenation of water in vapor phase catalysis.
It can also be prepared from β-hydroxyethylaminoethylamine and n-hydroxyethylethylenediamine (HOCH2CH2NHCH2CH2NH2) in the presence of Ni/Al2O3 by high temperature dehydrogenation.
2-chlorophenone reacts with ammonia to form aminoketones, which are then dehydrated and oxidized to pyrazine