Synthesis and in vitro leishmanicidal activity of 2-(1-methyl-5-nitro-1H-imidazol-2-yl)-5-substituted-1,3,4-thiadiazole derivatives

A series of 2-(1-methyl-5-nitroimidazol-2-yl)-5-(1-piperazinyl, 1-piperidinyl and 1-morpholinyl)-1,3,4–thiadiazoles (3a–g) were synthesized and evaluated for in vitro leishmanicidal activity against Leishmania major promastigotes. The leishmanicidal data revealed that compounds 3a–g had strong and much better leishmanicidal activity than the reference drug pentostam. Compound 3c (piperazine analog) was the most active compound (IC₅₀ = 0.19 μM).