Synthesis and characterization of mono- and bicyclic heterocyclic derivatives containing 1,2,4-triazole, 1,3,4-thia-, and -oxadiazole rings

摘要

A series of new N- and S-substituted 1,3,4-oxadiazole derivatives were synthesized. 5-Pyri-din-3-yl-3-[2-(5-thioxo-4,5-dihydro-1,3,4-thiadiazol-2-yl)ethyl]-1,3,4-oxadiazole-2(37f)-thione and 5-[(5-(pyridin-3-yl)-1,3,4-oxadiazol-2-ylthio)methyl]-N-phenyl-1,3,4-thiadiazol-2-amine were formed by cyclization of 3-(5-pyridin-3-yl-2-thioxo-1,3,4-oxadi-azol-3(2H)-ylpropanimidohydrazide and 2-[(5-pyri-din-3-yl-1,3,4-oxadiazol-2-yl)thio]thiosemicarbazide with CS2 and H2SO4. On the other hand, a number of new bicyclic 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were synthesized. 6-Pyridin-3-ylbis[1,2,4]-triazolo[3,4-b:4',3'-d][1,3,4]thiadiazole-3(2H)-thione was synthesized by reaction of 6-(hydrazino)-3-pyri-dine-3-yl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole with CS2/KO}i/EtOH. The structures of the newly synthesized compounds were elucidated by the spectral and analytical data IR, Mass, and ~1H NMR spectra.