A facile and efficient one-pot synthesis of substitutedthieno[2,3-b]pyridines has been developed. Treatment of enaminones, such as 2-acetyl-3-(dimethylamino)propenamides and -propenoates, with 2-cyanothioacetamide in the presence of potassium carbonate in N,N-dimethylformamide at 80 ˚C followed by addition of methylene-active bromides at room temperature provided, via intramolecular cyclization,
已经开发了一种简便,高效的一锅法合成取代的噻吩并[2,3- b ]吡啶。在80°C下于N,N-二甲基甲酰胺中的碳酸钾存在下,用2-氰基硫代乙酰胺处理2-氨基-3-(二甲基氨基)丙烯酰胺和-丙烯酸酯等烯胺酮,然后在室温下添加亚甲基活性溴化物通过分子内环化提供2,3,5,6-四取代的噻吩并[2,3- b ]吡啶的温度为78-90%。该方案结合了噻吩并[2,3- b ]吡啶环的构建和修饰,增加了最终材料的结构多样性,这些最终产品来自易于获得的材料。 烯胺酮-环化-杂环-吡啶-2(1 H)-硫酮-噻吩并[2,3- b ]吡啶
Efficient Synthesis of Pyridin‐2(1<i>H</i>)‐ones From a Series of Readily Available Enaminones Under Mild Conditions
作者:Bao‐chang Gao、Yu‐feng Sun、Jun Wang、Li‐wu Zu、Xu Zhang、Wen‐bin Liu
DOI:10.1002/jhet.3333
日期:2018.12
A facile and efficient synthesis of substituted pyridin‐2(1H)‐ones has been developed by the reaction of readily available enaminones with malononitrile in ethanol at room temperature in yields of 85–95%. This protocol, which combines construction and modification of the pyridin‐2(1H)‐ones ring underVilsmeierconditions (dimethylformamide/POCl3), increases the structural diversity of the final products
A facile and efficient one-potsynthesis of polysubstituted pyridin-2(1H)-ones from readily available enaminones and the cyanomethyl sulfonium bromide salt in the presence of cesium carbonate is developed, and a mechanism involving sequential nucleophilic vinylic substitution (S(N)V), intramolecular nucleophilic cyclization and dealkylation reactions is proposed.
A facile one-pot synthesis of pyrimidin-4(3H)-ones was developed via reactions of a series of readily available 3-aminopropenamides with varied Vilsmeier reagents, and a mechanism involving sequential halogenation, formylation, and intramolecular nucleophilic cyclization is proposed.