Design and synthesis of D‐π‐A fluorescent dyes based on nicotinonitrile and azobenzene derivatives

Abstract

Study the synthesis and fluorescent properties of a new series of D‐π‐A fluorescent dyes based on nicotinonitrile and azobenzene is the main objective for this work. Reduction with Zn/HCl, diazotization with HCl/NaNO2, and coupling using catalytic NaOH or AcONa are simple applied methods. Where, nicotinonitrile 3 was synthesized via reduction of nitro derivative 1 followed by diazotization with HCl/NaNO2 in acetic acid. The formed benzene diazonium chloride was coupled with several activated phenols, aniline, and α‐CH acids to yield the respective azo dyes 4‐11 in moderate to good yield. Dyes 11a‐d subjected to intermolecular cyclization with hydrazine hydrate resulted in pyrazole dyes 12‐15 in moderate yield. Dyes containing pyrazole moiety or electron‐withdrawing groups at the sixth position of pyridine nucleus exhibit stronger blue‐green emission (λfl.max = 503, 507, 500, 501, 502, 493, and 514 nm) than that of the rest of compounds.

NiO‐Nanoparticles as green catalyst for an efficient synthesis of 4‐iminopyrido[1,2‐a]pyrimidine fluorophores via one pot cyclization of α‐aminonicotinonitrile

“…[ 16–19 ] Nickel oxide nanoparticles (NiO‐NPs) have innumerable applications such as biomedical (e.g., cell separation, magnetic resonance imaging, drug delivery, and biomedical detection), wastewater dye degradation, and the ability to modernize the agriculture field. [ 20 ] Recently, the one‐pot multicomponent, [ 21, 22 ] microwave, [ 23–26 ] ultrasonic, [ 27 ] solvent‐free, [ 22 ] metal‐free, [ 28 ] and nano catalytic conditions [ 16 ] are some green approaches which have been developed by our research team for the synthesis of multifunctional heterocyclic scaffolds with a wide range of applicable interest. Herein, we synthesized a new series of 2‐aryl(heteroaryl)‐7‐chloro‐8‐(4‐chlorophenyl)‐4‐imino‐4H‐pyrido[1,2‐ a ]pyrimidine‐3,9‐dicarbonitrile utilizing NiO‐NPs as an efficient, cheap, soft, chemically stable and readily available nanocatalyst.…”

Effect of a Substituent in the Fourth Position on the Optical Properties of 2-Oxonicotinonitriles

“…The pyridone fragment, in particular, the 2-oxonicotinonitrile one, causes the appearance of fluorescent properties in the molecule [25][26][27][28][29][30][31][32][33][34][35][36]. However, there is practically no information in the literature on the systematic study of the effect of an individual substituent on the photophysical properties of such compounds, despite the fact that the optical properties can be finely tuned by introducing individual functional groups.…”

An efficient synthesis of 4,6‐diarylnicotinonitrile‐acetamide hybrids via 1,2,3‐triazole linker as multitarget microbial inhibitors

“…The second reason is the use of azide‐alkyne cycloaddition methodology in the synthesis of such moiety. Recently, our approaches are directed to development of new hybrid nicotinonitrile scaffolds with pharmacophore and fluorophore properties [18,23–27]. The current work describes an efficient synthetic click coupling between acetylenic nicotinonitrile and azidoacetamide aimed to form bacterially active hybrid molecules via 1,2,3‐triazole linker.…”