Invention is related to novel compounds -5-aryl-4-(5-substituted 2,4-dihydroxyphenyl)-1,2,3-thiadiazoles with general formula (I). The compounds can be used in biomedicine as active ingredients in pharmaceutical formulations, because they inhibit Hsp90 chaperone which participate in cancer progression. This invention is also related to new intermediate compounds which are used for the synthesis of thiadiazoles of general formula (I).