Synthesis, Character Of Sulfur Ether Derivations Containing 1,3,4-oxadiazole And 1,3,4-thiadiazole

1,3,4-thiazdiazole and 1,3,4-oxiadiazole are important representatives of nitrogen-containing heterocyclic compounds. Commonly, they possess versatile biological activities, and are used as anti-bacterial, antifigural anti-inflammation, anti-cancer, and other drugs. It is useful in improving biological activity of active group and affinity between related receptor and ligand to connect active groups with electron donor atom (such as:S, O).A series of novel sulfur ethers containing 1,3,4-oxadiazole and 1,3,4-thiadiazole were synthesized by means of combining the active segments 1,3,4-thiadiazole and 1,3,4-oxadiazole heterocycles, according to the superpostion principle of reinforcement of biological activities. The intermediates of biacyl thiosemicarbazide derivatives (A1-A27) were obtained by the addition reaction of hydrazide (4a-4f) with aroyl isothiocyanates(g-k). Finally, the target compounds were prepared by cyclization of corresponding intermediate (A1-A27) in the presence of CH3OH/H2SO4 at room temperature. The synthetic routes were shown in Scheme 1. All target products (B1～B27) and their important intermdiates A1～A27 have not been reported in literature, and their structures were confirmed by IR spectra, 1H NMR spectra, ESI-MS or HRMS techniques.