作者:M. Fernanda Proença、Magdi E. Zaki、Brian L. Booth
DOI:10.1055/s-2005-872700
日期:——
1-Aryl-5-amino-4-cyanoformimidoyl imidazoles 1 were reacted with methyl cyanoacetate, under mild experimental conditions, leading to 3-aryl-6,7-dicyanoimidazo[4,5-b]pyridine-5-ones 5, isolated after neutralization of their ammonium salts 4. A reaction intermediate, imidazole 3d, the precursor of the bicyclic structure 5d, could be isolated under carefully controlled experimental conditions and was shown to cyclize to imidazo[4,5-b]pyridine-5-one (4d, isolated as the DBU salt) after reflux in ethanol, in the presence of DBU.
在温和的实验条件下,1-芳基-5-氨基-4-氰基亚氨代咪唑1与甲基氰基乙酸酯反应,生成3-芳基-6,7-二氰基咪唑并[4,5-b]吡啶-5-酮5,这些产物在它们的铵盐4中和后被分离出来。在严格控制的实验条件下,可以分离出反应中间体咪唑3d,它是双环结构5d的前体,在有DBU存在下,在乙醇中回流后,它能够环化成咪唑并[4,5-b]吡啶-5-酮(4d,以DBU盐的形式分离)。