Synthesis, structural characterization, X-ray, solvatochromism and biological properties of 7-hydroxy-2-(2-hydroxy-5-(phenyldiazenyl)benzylidene)amino)-4-phenyl-4H-chromene-3-carbonitrile

The new chromene-based azomethine dyes were synthesized via two-component coupling of 2-amino-7-hydroxy-4H-chromene with 2-hydroxy-5-(aryldiazenyl)benzaldehyde and characterized by elemental analyses, mass, NMR, IR, UV-Vis spectroscopy and X-ray diffraction analysis. Easily available and easy work-up are the key features of the present method. The pyran, chromene moiety and aromatic rings in the azomethine linkage are flattened. Intramolecular hydrogen bonding is possible between hydroxyl group and the imine nitrogen atom. All of the compounds except 2-amino-7-hydroxy-4H-chromene exhibited activity against Gram-positive bacteria Bacillus cereus, Staphylococcus aureus and Staphylococcus epidermidis. The compounds displayed weak to mild antioxidant activity compared with ascorbic acid as standard. (C) 2016 Published by Elsevier B.V.