An azacycloalkane that consists of a six-membered ring containing two nitrogen atoms at opposite positions. ChEBI: Piperazine is an azacycloalkane that consists of a six-membered ring containing two nitrogen atoms at opposite positions. It has a role as an anthelminthic drug. It is a saturated organic heteromonocyclic parent, an azacycloalkane and a member of piperazines. It is a conjugate base of a piperazinium(2+).