1,4-Diazacycloheptane 1H-1,4-Diazepine, hexahydro- 5-23-03-00240 (Beilstein Handbook Reference) 505-66-8 BRN 0102711 EINECS 208-016-1 Hexahydro-1,4-diazepine Homopiperazine Perhydro-1,4-diazepine Trimethyleneethylenediamine