komposti eteroċikliċi beteroatom[i] tannitroġenu biss li fihom pirimidine bċirku idroġenat jew le jew piperzine bċirku flistruttura (minbarra malonylurea aċidu barbituriku u dderivati tiegħu allobarbital inn amobarbital inn barbital inn butalbital inn butobarbital inn ċiklobarbital inn metilphenobarbital inn pentobarbital inn fenobarbital inn secbutabarbital inn secobarbital inn vinilbital inn loprazolam inn mecloqualone inn methaqualone inn u zipeprol inn u limlieħ tagħhom)