The clean synthesis and confirmatory structural characterization of new 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-cyano based on Kojic acid

A valuable and clean method was developed for the synthesis of the group of different novel 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitriles containing a 2-aminopyran moiety by using of azido kojic acid and various 2-arylidinemalononitriles in the presence of NH4Cl as a catalyst in a green solvent (ethanol) with excellent yields. All structures were analyzed by FT-IR, H-1, C-13 NMR spectroscopy, and representatively, one compound was analyzed by X-ray crystallography technique. Crystallographic analyses indicated that of this compound a dimer formed via two weak intermolecular hydrogen bonds with d((N center dot center dot center dot O)) distances of 2.927 angstrom and made a 14-membered ring with centrosymmetric (C-i) form. [GRAPHICS] .