New triazolothiadiazine derivatives were synthesized via the ring closure reaction of 4-amino-5-substituted-2,4-dihydro-3H-1,2,4-triazol-3-thiones with phenacyl bromides. The compounds were tested in vitro against various Candida species and compared with ketoconazole. Among these compounds, the compound bearing cyclohexyl moiety and p-chlorophenyl substituent on triazolothiadiazine ring (2i) was found
[image omitted] The aim of this study is to synthesize new triazole derivatives and investigate their antimicrobial activities. 4-Amino-5-(2-cyclohexylethyl)-3-[N-(benzothiazole-2-yl)acetamido]thio-4H-1,2,4-triazole and 4-amino-5-[2-(4-hydroxyphenyl)ethyl]-3-[N-(benzothiazole-2-yl)acetamido]thio-4H-1,2,4-triazole derivatives were prepared by the reaction of 2-chloro-N-(benzothiazole-2-yl)acetamides with 4-amino-5-(2-cyclohexylethyl)-2,4-dihydro-3H-1,2,4-triazol-3-thione and 4-amino-5-[2-(4-hydroxyphenyl)ethyl]-2,4-dihydro-3H-1,2,4-triazol-3-thione, respectively. The structures of these compounds were elucidated by infrared, 1H NMR, 13C NMR, mass spectra, and elemental analysis. The synthesized compounds were screened for their antimicrobial activities against various Candida species and pathogenic bacteria. Compound IIIg and compound IIIi were found to be the most potent derivatives against Candida species and tested bacteria, respectively.