Intermolecular Cyclization of Diethanolamine and Methylamine to N,N′-Dimethylpiperazine over Zeolites under High Pressure

Synthesis of N,N′-dimethylpiperazine via intermolecular cyclization of diethanolamine and methylamine has been investigated under high pressure conditions using zeolites and montmorillonite K10 for the first time. The HZSM-5(30) is particularly effective for N,N′-dimethylpiperazine formation and the catalyst can be reused many times without significant loss of activity.