Synthesis, cytotoxic characterization, and SAR study of imidazo[1,2-b]pyrazole-7-carboxamides.

The synthesis and in vitro cytotoxic characteristics of new imidazo[1,2-b]pyrazole-7-carboxamides were investigated. Following a hit-to-lead optimization exploiting 2D and 3D cultures of MCF-7 human breast, 4T1 mammary gland, and HL-60 human promyelocytic leukemia cancer cell lines, a 67-membered library was constructed and the structure-activity relationship (SAR) was determined. Seven synthesized analogues exhibited sub-micromolar activities, from which compound 63 exerted the most significant potency with a remarkable HL-60 sensitivity (IC50  = 0.183 μM).