A facile synthesis of 2,7-diazapyrene

Abstract

2,7-Diazapyrene is synthesized in three high-yield steps from commercially available 1,4,5,8-naphthalene tetracarboxylic dianhydride, which first reacts with concentrated ammonium hydroxide solution at room temperature to give 1,4,5,8-naphthalenetetracarboxylic diimide (96%). The latter compound is subsequently reduced with borane in refluxing tetrahydrofuran to give 1,2,3,6,7,8-hexahydro-2,7-diazapyrene (77%), which in turn is oxidized with manganese dioxide in refluxing benzene giving 2,7-diazapyrene (71%).