A series of previously undescribed 3-amino-4,5,6,7-tetrahydrothieno[2,3- b ]pyridines was prepared in 44–79% yields through alkylation of N -methylmorpholinium 3-cyano-4-(4-methoxyphenyl)-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolate followed by Thorpe–Ziegler cyclization in the presence of KOH. An in silico predictor analysis was conducted to determine the bioavailability parameters and potential protein targets for the new compounds. Under laboratory experimental conditions on sunflower seedlings, some of the synthesized compounds demonstrated a moderate antidote effect against the herbicide 2,4-D.

Исследованы люминесцентные комплексы тербия и европия с тетрафтортерефталевой кислотой и фенантролином для применения в термометрии. Показано, что в отличие от смеси индивидуальных комплексов, демонстрирующих различную скорость фотодеградации, биметаллический комплекс сохраняет стабильное соотношение интенсивностей полос излучения Tb3+ и Eu3+ при общем снижении интенсивности люминесценции. Разработаны композитные материалы на основе синтезированных комплексов в полиимидных и полистирольных матрицах, сочетающие термочувствительные свой­ства с механической устойчивостью. Полученные результаты открывают перспективы создания стабильных люминесцентных термометров для биологических и микроэлектронных применений.

Morpholinium (N-methylmorpholinium) 4-aryl-6-oxo-3-cyano-1,4,5,6-tetrahydropyridine-2-thiolates obtained by the reaction of cyanothioacetamide and aromatic aldehydes with Meldrum’s acid in the presence of a base undergo a tandem S-alkylation–Thorpe–Ziegler heterocyclization reaction upon treatment with α-halo carbonyl compounds in the presence of excess KOH. Predictive in silico analysis and molecular docking were performed for the newly synthesized 3-amino-4-aryl-6-oxo-4,5,6,7-tetrahydrothieno[2,3-b]pyridines to identify bioavailability parameters and potential protein targets. In laboratory experiments on sunflower seedlings, some of the compounds exhibited a pronounced safening effect against the herbicide 2,4-D (2,4-dichlorophenoxyacetic acid).

The paper presents an effective method for synthesizing new 3-amino-4-aryl-6-oxo-4,5,6,7-tetrahydrothieno[2,3-b]pyridines via tandem S-alkylation and Thorpe–Ziegler heterocyclization. The initial reagents were 4-aryl-6-oxo-3-cyano-1,4,5,6-tetrahydropyridine-2-thiolates of morpholinium (or N-methylmorpholinium). Their reaction with α-halocarbonyl compounds in excess alcoholic KOH gave target products in 59–78% yields. Structures were confirmed by IR, NMR, and elemental analysis; the C4 chiral configuration was established. In-silico analysis showed the compounds meet Lipinski’s “rule of five”, with predicted high gastrointestinal absorption and blood–brain barrier penetration; toxicological assessment gave mixed results. Biological testing on sunflower seedlings revealed some derivatives have a pronounced antidote effect against the herbicide 2,4-D, assessed via increased hypocotyl and root lengths. The synthetic approach thus yields heterocyclic compounds promising as plant protectors in agrochemistry, warranting further study of their activity and mechanisms.