Practical synthesis of 5H-pyrido[2',1:2,3]imidazo[4,5-b]indoles by Cu- catalyzed double C-N coupling reactions

Fluorescent active small molecules containing 5H-pyrido [12',1':2,3]imidazo [4,5-b]indole core could be successfully prepared by Cu-catalyzed double C-N coupling reaction from 3-bromo-2-(2-bromophenyl) imidazo [1,2-a]pyridine with different amines in high yields. DMSO, a green solvent played a key role for the success of this double C-N coupling reaction. This method may find potential applications not only in pharmaceutical chemistry but also in materials science. (c) 2023 Published by Elsevier Ltd.