RAS protein plays a key role in cellular proliferation and differentiation. RAS gene mutation is a known driver of oncogenic alternation in human cancer. RAS inhibition is an effective therapeutic treatment for solid tumors, but RAS protein has been classified as an undruggable target. Recent reports have demonstrated that a covalent binder to KRAS protein at a mutated cysteine residue (G12C) is effective for the treatment of solid tumors. Here, we report a series of 1-{2,7-diazaspiro[3.5]nonan-2-yl}prop-2-en-1-one derivatives as potent covalent inhibitors against KRAS G12C identified throughout structural optimization of an acryloyl amine moiety to improve in vitro inhibitory activity. From an X-ray complex structural analysis, the 1-{2,7-diazaspiro[3.5]nonan-2-yl}prop-2-en-1-one moiety binds in the switch-II pocket of KRAS G12C. Further optimization of the lead compound (5c) led to the successful identification of 1-[7-[6-chloro-8-fluoro-7-(5-methyl-1H-indazol-4-yl)-2-[(1-methylpiperidin-4-yl)amino]quinazolin-4-yl]-2,7-diazaspiro[3.5]nonan-2-yl]prop-2-en-1-one (7b), a potent compound with high metabolic stabilities in human and mouse liver microsomes. Compound 7b showed a dose-dependent antitumor effect on subcutaneous administration in an NCI-H1373 xenograft mouse model.

RAS蛋白在细胞增殖和分化中起关键作用。RAS 基因突变是人类癌症中致癌基因改变的已知驱动因素。RAS抑制是实体瘤的有效治疗方法，但RAS蛋白已被归类为不可成药的靶点。最近的报道表明，在突变的半胱氨酸残基 (G12C) 上与 KRAS 蛋白共价结合可有效治疗实体瘤。在这里，我们报告了一系列 1-{2,7-diazaspiro[3.5]nonan-2-yl}prop-2-en-1-one 衍生物作为针对 KRAS G12C 的有效共价抑制剂，在丙烯酰胺部分的结构优化过程中发现以提高体外抑制活性。从 X 射线复杂结构分析，1 -{2,7-diazaspiro[3.5]nonan-2-yl}prop-2-en-1-one 部分结合在 KRAS G12C 的 switch-II 口袋中。先导化合物 ( 5c ) 的进一步优化导致成功鉴定了 1-[7-[6-chloro-8-fluoro-7-(5-methyl-1H-indazol-4-yl)-2-[(1 -methylpiperidin-4-yl)amino]quinazolin-4-yl]-2,7-diazaspiro[3.5]nonan-2-yl]prop-2-en-1-one ( 7b )，一种具有高代谢稳定性的有效化合物在人和小鼠肝微粒体中。在NCI-H1373异种移植小鼠模型中，化合物7b对皮下给药显示出剂量依赖性抗肿瘤作用。