Synthesis and evaluation of novel 3,4,6-substituted 2-quinolones as FMS kinase inhibitors

Abstract A series of 3,4,6-substituted 2-quinolones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). The fully optimized compound, 4-(4-ethyl-phenyl)-3-(2-methyl-3 H -imidazol-4-yl)-2-quinolone-6-carbonitrile 21b , has an IC 50 of 2.5 nM in an in vitro assay and 5.0 nM in a bone marrow-derived macrophage cellular assay. Inhibition of FMS signaling in vivo was also demonstrated in a mouse pharmacodynamic model.