Herein we report the discovery of 1-(5-(tert-butyl)isoxazol-3-yl)-3- (3-fluorophenyl)urea derivatives as new FLT3 inhibitors that are able to overcome the drug resistance mutations: the secondary D835Y and F691L mutations on the basis of the internal tandem duplications (ITD) mutation of FLT3 (FLT3-ITD/D835Y and FLT3-ITD/F691L, respectively). The most potent compound corresponds to 1-(5-(tert-butyl)isoxazol-3-yl)-3-(4-((6,7-dimethoxyquinolin-4-yl)oxy)-3- fluorophenyl)urea (4d), which showed IC₅₀s (half maximal inhibitory concentrations) of 0.072 nM, 5.86 nM and 3.48 nM against FLT3-ITD, FLT3-ITD/F691L and FLT3-ITD/D835Y, respectively. Compound 4d also showed good selectivity for FLT3 in a kinase profiling assay. Collectively, 4d could be a good lead compound and deserves further in-depth studies.

在这里，我们报告发现1-（5-（叔丁基）异恶唑-3-基）-3-（3-氟苯基）脲衍生物作为能够克服药物抗性突变的新型FLT3抑制剂的发现：次级D835Y和F691L突变基于FLT3的内部串联重复（ITD）突变（分别为FLT3-ITD / D835Y和FLT3-ITD / F691L）。最有效的化合物对应于1-（5-（叔丁基）异恶唑-3-基）-3-（4-（（6,7-二甲氧基喹啉-4-基）氧基）-3-氟苯基）脲（4d），分别显示针对FLT3-ITD，FLT3-ITD / F691L和FLT3-ITD / D835Y的IC ₅₀ s（半数最大抑制浓度）分别为0.072 nM，5.86 nM和3.48 nM。化合物4d在激酶谱分析中也显示出对FLT3的良好选择性。集体，4d 可能是很好的铅化合物，值得进一步深入研究。