Design, Synthesis, andIn VitroAntileishmanial and Antitumor Activities of New Tetrahydroquinolines

A novel series of tetrahydroquinolines containing acetohydrazide, oxopyrazole, oxothioxodihydropyrazole, and thioxotriazole have been synthesized. Antileishmanial, antitumor, and cytotoxicity activities of synthesized compounds were evaluatedin vitro. Antileishmanial activity of the most synthesized compounds showed tremendous activity towardsLeishmaniamajor.Most of the test compounds exhibited significant level of tumor inhibition. The tetrahydropyrano[2,3‐b]quinolin‐2‐one6and 4‐oxo‐4H‐pyrazol‐3‐yloxytetrahydroquinoline‐3‐carbonitrile derivatives18showed 100% tumor inhibition comparable with standard drug vincristine (100% tumor inhibition). Tetrahydroquinolines under investigation showed cytotoxicity with LD50values in the range 0.56–3.01 μg/mL compared with standard drug MS‐222 with LD50value of 4.30 μg/mL. The presence of a pyrazole ring markedly improved the activity profiles of tetrahydroquinoline. All newly synthesized compounds were characterized by IR,1H NMR, and MS.