A novel process for the synthesis of 3,5-diaryl-1,2,4-thiadiazoles from aryl nitriles

Electrochemical Synthesis of 3,5‐Disubstituted‐1,2,4‐thiadiazoles through NH4I‐Mediated Dimerization of Thioamides

“…Other substrates, such as aryl nitriles, aryl amidines, and 3,5‐dichloro‐1,2,4‐thiadiazole, have also been reported for the synthesis of thiadiazoles. However, these methods typically require stoichiometric amounts of oxidizing agents, excessive amounts of sulfur and LiOtBu, or expensive palladium catalyst. Therefore, a green, facile, and sustainable approach for 1,2,4‐thiadiazoles synthesis is urgently needed.…”

Isolation of unique heterocycles formed from pyridine-thiocarboxamides as diiodine, iodide, or polyiodide salts

“…[1][2][3][4][5] Numerous methods have been developed to access these moieties, including dimerization of aryl nitriles in the presence of ammonium sulfide, as well as the cyclization reaction of nitriles or imine esters with thioamides. [6][7][8][9] Perhaps the most straightforward method developed is the oxidative cyclization of two thioamides. Techniques have been developed utilizing specialized reagents such as phosphovanadomolybdic acid or pseudocyclic benziodoxole triflate.…”

Visible light promoted formation of N─S bond by photocatalyst Eosin Y

“…23 However, other fascinating biological effects are as cathepsin B inhibitors, 24 as allosteric modulators binding at secondary binding site of biomolecules, 25 non-ATP competitive GSK-3 inhibitors 26 and as dual 5-lipoxygenase and cyclooxygenase inhibitors. 27 1,2,4-thiadiazoles have been synthesized by various methods, like copper-catalyzed reaction of amidine hydrochlorides with isothiocyanates, 28 from aryl nitriles in 1-butyl-3-methylimidazolium bromide, 29 molecular iodine catalyzed N─S bond formation, 30 copper-catalyzed aerobic oxidative annulation, 31 and electrochemical intermolecular dehydrogenative S─N coupling. 32 Despite these interesting reports for synthesis of these moieties, visible light promoted methods for synthesis of 1,2,4-thiadiazoles remains a relatively unexplored area.…”