Metal carbonyl mediated rearrangement of 5-(2-oxoalkyl)-1,2,4-oxadiazoles: synthesis of fully substituted pyrimidines
作者:Ekaterina E. Galenko、Timur O. Zanakhov、Mikhail S. Novikov、Alexander F. Khlebnikov
DOI:10.1039/d3ob00148b
日期:——
6-dihydropyrimidine-5-carboxylates can be easily prepared by a metal carbonyl mediated rearrangement of ethyl 3-oxo-2-(1,2,4-oxadiazol-5-yl)propanoates. The irradiation of a mixture of oxadiazoles and Fe(CO)5 in wet solvents with a 365 nm LED at room temperature for 2 h followed by heating at 80 °C for 2 h gives pyrimidines in up to 90% yield. This procedure enables the preparation of 6-oxo-1,6-dihydrop
通过金属羰基介导的 3-氧代-2-(1,2,4-恶二唑-5-基) 丙酸乙酯的重排,可以很容易地制备各种取代的 6-氧代-1,6-二氢嘧啶-5-羧酸乙酯。在室温下用 365 nm LED 照射湿溶剂中恶二唑和Fe(CO) 5的混合物2 小时,然后在 80 °C 下加热 2 小时,得到高达 90% 产率的嘧啶。该程序能够制备 6-oxo-1,6-dihydropyrimidine-5-carboxylates,在 C2 位置具有各种芳基取代基,在 C4 位置具有烷基或芳基取代基。1-(1,2,4-Oxadiazol-5-yl)propan-2-ones 类似地得到 6-methylpyrimidin-4(3 H)-ones,尽管产量较低。Ethyl 6-oxo-1,6-dihydropyrimidine-5-carboxylates 可以很容易地在 C6 位置通过溴化修饰,然后进行交叉偶联反应,得到带有吡啶基、氨基和乙炔基取代基的