A novel concept—the pseudo-intramolecular process—is applied to the synthesis of multiply functionalized heterocyclic compounds. Acidic α-nitro-δ-keto nitrile easily forms an ammonium salt upon treatment with an amine. When the amine is liberated under equilibrium, an intimate pair, namely, a nucleophilic amine and an electrophilic keto nitrile are located close to each other, is formed; thus the amine efficiently attacks a cyano group of keto nitrile. As a result of subsequent cyclization, 1,4-dihydropyridines containing an amino and a nitro group at the vicinal positions as a partial structure are afforded.
一种新概念--假分子内过程--被应用于多官能化
杂环化合物的合成。酸性 α-硝基-δ-酮腈在与胺处理后很容易形成
铵盐。当胺在平衡状态下释放出来时,亲核胺和亲电酮腈就形成了亲密的一对,从而使胺有效地攻击酮腈的
氰基。随后的环化反应产生了部分结构的 1,4-
二氢吡啶,其邻接位置含有一个
氨基和一个硝基。