6-Chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine

As part of our ongoing scaffold-hopping work on an antikinetoplastid 3-nitroimidazo[1,2-a]pyridine scaffold, we explored 3-nitroimidazo[1,2-b]pyridazine as a potential new series. Using conditions previously described by lab, obtained 6-chloro-3-nitro-2-[(phenylsulfonyl)methyl]imidazo[1,2-b]pyridazine with 54% yield. In vitro activity this compound was evaluated against both the promastigote form Leishmania donovani, axenic amastigote infantum and trypomastigote blood stream Trypanosomabrucei brucei, its influence cell viability assessed HepG2 line. However, despite good T. b. brucei (EC50 = 0.38 µM), it showed poor solubility in (CC50 > 7.8 µM) L. amastigotes 1.6 culture media, associated loss 15.6 µM).