Effective synthesis of new benzo-fused macrocyclic and heteromacrocyclic bis(Schiff bases)

In this study, the synthons 2-hydroxy-5-((arylthio)methyl)benzaldehydes were reacted with 1,ω-dihaloalkanes to produce the corresponding bis(aldehydes). The previous precursors were reacted with the appropriate alkane-1,ω-diamines in glacial acetic acid to yield a new series of macrocyclic bis(Schiff bases). Following that, a new series of thiamacrocyclic bis(Schiff bases) were synthesized in glacial acetic acid via sodium acetate-mediated cyclocondensation of the appropriate of 2,2'-(alkane-1,ω-diylbis(sulfanediyl))dianiline dihydrochloride with bis(aldehydes). Moreover, bis(4-amino-4H-1,2,4-triazole-3-thiol), linked to propane core via thioether, was cyclocondensed with bis(aldehydes) in glacial acetic acid to prepare new S-triazole-fused thiamacrocyclic bis(Schiff bases). The previous macrocycles were reacted with two equivalents of iodomethane in methanolic sodium methoxide solution to give macrocyclic bis(methylthio) derivatives. Surprisingly, the reaction of thieno[2,3-b]thiophene-linked bis(4-amino-3-phenyl-4H-1,2,4-triazole) with the appropriate bis(aldehydes) in glacial acetic acid resulted in a new series [1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-fused macrocycles. All of the new macrocycles were synthesized with good to excellent yields, and their structures were deduced using elemental and spectral data.