Synthesis of 2,9-Dichloro-1,10-phenanthroline from N,N'-Annelated Phenanthrolinediones

Article abstract of DOI:10.1246/bcsj.63.2710

Though the chlorination of an N,N'-annelated phenanthrolinedione, 3,6,7,9-tetrahydro-5H-<1,4>diazepino<1,2,3,4-lmn><1,10>phenanthroline-3,9-dione, gave 2,9-dichloro-1,10-phenanthroline, another dione, 3,5,6,8-tetrahydropyrazino<1,2,3,4-lmn><1,10>phenanthroline-3,8-dione, did not.It demonstrated a simultanous introduction of two chlorine substituents to non-substituted 1,10-phenanthroline via only the former intermediate.