作者:Dániel Nagy、Mihály V. Pilipecz、László A. Kiss、Anna Alekszi-Kaszás、András Simon、Gitta Z. Schlosser、Péter Nemes、Tamás R. Varga
DOI:10.1080/00397911.2021.1913504
日期:——
4-triazol-3-ones from cyclic β-nitroenamines in four steps is provided, with an overall yield of 8–70%. The nitrazone to amidrazone conversion (third step) could not proceed in absence of LiBr catalyst, and the crucial role of this mild Lewis acid is emphasized. The last cyclization step required the boosting effect of N-methylimidazole and elevated reaction temperature, as well. This reliable synthesis is highly
摘要 提供了由环状β-硝基烯胺分四步制备代表性选择的2-芳基-4,5-二取代-1,2,4-三唑-3-酮,总产率为8-70%。在没有溴化锂催化剂的情况下,硝腙到脒腙的转化(第三步)无法进行,强调了这种温和的路易斯酸的关键作用。最后的环化步骤也需要N-甲基咪唑的促进作用和升高的反应温度。这种可靠的合成方法也非常通用,它可以提供具有潜在药理活性的 2,4,5-三取代-1,2,4-三唑-3-酮的化学库。强调了伴随着硝基烯胺的广泛可转化性的umpolung的有用性。