Using a cell-based high-throughput screen, we identified isoxazolo[5,4-d]pyrimidines as novel small-molecule correctors of the cystic fibrosis mutant protein ÎF508-CFTR. 22 Isoxazolo[5,4-d]pyrimidine analogues were synthesized and tested. Synthesis of the key intermediate, 5-amino-3-arylisoxazole-4-carboxamide, was accomplished by nitrile oxide cycloaddition to (2-amino-1-cyano-2-oxoethyl)sodium. Formation of 3-arylisoxazolo-[5,4-d]pyrimidin-4(5H)-one and chlorination gave 4-chloro-3-arylisoxazolo[5,4-d]pyrimidine. Finally, functionalization at C-4 of the pyrimidine ring by nucleophilic substitution gave the targeted isoxazolo[5,4-d]pyrimidines. Six of the reported analogues had low micromolar potency for increasing halide transport in ÎF508-CFTR cells.
通过基于细胞的高通量筛选,我们发现
异噁唑并[5,4-d]
嘧啶是新型的囊性纤维化突变蛋白δF508-CFTR 的小分子校正剂。22 我们合成并测试了
异噁唑并[5,4-d]
嘧啶类似物。关键中间体 5-
氨基-3-芳基
异恶唑-4-甲酰胺的合成是通过腈氧化物与(2-
氨基-1-
氰基-2-氧代乙基)
钠的环加成反应完成的。形成 3-芳基
异恶唑并[5,4-d]
嘧啶-4(5H)-酮并进行
氯化反应,得到 4-
氯-3-芳基
异恶唑并[5,4-d]
嘧啶。最后,在
嘧啶环的 C-4 处通过亲核取代进行官能化,得到了目标
异噁唑并[5,4-d]
嘧啶。在已报道的类似物中,有六种在ÎF508-CFTR细胞中增加卤化物转运的微摩尔效力较低。