Synthesis of macrocycles incorporating azo-bis(azofurazan) framework

A series of macrocycles containing four furazan rings bonded by three azo bonds 2, 5 and 7 have been synthesized from the common precursor, 3-amino-3'-nitro(azofurazan) 3. The macrocycles closure is a result of N=N bond formation at oxidative cyclization of corresponding bis(3-aminofurazan-4-yl) precursors. X-Ray crystal structures of macrocycles 2, 2 center dot AcOH, 11 and 13 are reported.