Reaction of 3-azidopropyl methanesulfonate-with triphenylphosphine produced the 1,4-bis(triphenylphosphino)piperazine 5 by intermolecular cyclization, instead of formation azidine derivatives by an intramolecular pathway. Structural formulation of 5 was achieved by both spectral and X-ray crystal analysis. Hydrolysis of 5 under basic condition gives piperazine, whereas reaction of lithium diphenylphosphide with 5 produced 1,2-bis(diphenyl-phosphino)ethane (dppe) exclusively.
