Synthesis and anti-HIV activity of new chiral 1,2,4-triazoles and 1,3,4-thiadiazoles

5-substituted 4-(4-chlorophenyl)-4H-1,2,4-triazol-3-thiones 3 and 2-substituted 5-(4-chlorophenylamino)-1,3,4-thiadiazoles 4 were prepared from the intermediate thiosemicarbazides 2 under basic and acidic conditions, respectively. The thiosemicarbazides, in turn, were prepared by the reaction of hydrazides 1 with 4-chlorophenylisothiocyanate in MeOH. Some of the new synthesized compounds were assayed against HIV-1 and HIV-2 in MT-4 cells. All the compounds were inactive except 3f, which showed an EC50 value of 23.9 mu g/mL and 9.9 mu g/mL against HIV-1 and HIV-2 with a therapeutic index of 3 and 7, respectively. it means that compound 3f was cytotoxic to MT-4 cells at CC50 of 72.7 mu g/mL in both strains. (c) 2007 Wiley Periodicals, Inc.