Synthesis of 1,2-dihydropyridine, Arylidene, Hydrazide, and Terthienylnicotin-amidine Hydrochloride Analogs: Theoretical Studies, and Antioxidant Activity Assessment

In the current work, we have utilized the reactivity of N-(4-acetylphenyl)-2-(4-formylphenoxy)acetamide for the synthesis of novel series of 1,2-dihydropyridines, Aryli-denes, and hydrazides. Our strategies were prolonged for the synthesis of novel ter-thienylnicotinamidine hydrochloride salt through a Stille coupling reaction of 6-(5'-bromo-[2,2'-bithiophen]-5-yl)nicotinonitrile with 2-tributyltin thiophene followed by treatment with lithium trimethylsilylamide and subsequent hydrolysis. The newly prepared structures were well-elucidated by analytical and spectral data (IR,¹H-NMR,¹³C-NMR, MS, and elemental analysis). The theoretical studies of terthienylnicotin-amidine verified that the other atoms that carry a high density of positive values are consid-ered active centers for the electron acceptor. The novel synthesized compounds were efficiently established by spectroscopic data and elemental analysis. The antioxidant activity of the synthesized arylidene, hydrazide, and dihydropyridine compounds was assessed by ABTS^•+ free radical assay. The results verified that the transformation of N-(4-acetylphenyl)-2-(4-formylphenoxy)acetamide (47.6%) into hy-drazide analogs provided remarkable antioxidant activity (78.1, and 60.3%).