Hosseini Hajar, Bayat Mohammad
Department of Chemistry, Faculty of Science, Imam Khomeini International University Qazvin Iran
RSC Adv. 2019 Mar 5;9(13):7218-7227. doi: 10.1039/c9ra00350a. eCollection 2019 Mar 1.
A highly efficient and straightforward synthesis of N-fused heterocyclic compounds including '-(1-(4-nitrophenyl)ethylidene)imidazo[1,2-]pyridine-6-carbohydrazide and '-(1-(4-nitrophenyl)ethylidene)pyrido[1,2-]pyrimidine-7-carbohydrazide derivatives is successfully achieved a five-component cascade reaction utilizing cyanoacetohydrazide, 4-nitroacetophenone, 1,1-bis(methylthio)-2-nitroethylene and various diamines in a mixture of water and ethanol. The new efficient domino protocol involving a sequence of ,-acetal formation, Knoevenagel condensation, Michael reaction, imine-enamine tautomerization and N-cyclization as key steps. The merit of this catalyst free approach is highlighted by its easily available starting materials, operational simplicity, clean reaction profile, the use of environmentally benign solvents and tolerance of a wide variety of functional groups.
通过在水和乙醇的混合物中利用氰基乙酰肼、4-硝基苯乙酮、1,1-双（甲硫基）-2-硝基乙烯和各种二胺进行五组分串联反应，成功实现了包括α-(1-(4-硝基苯基)亚乙基)咪唑并[1,2-a]吡啶-6-碳酰肼和α-(1-(4-硝基苯基)亚乙基)吡啶并[1,2-a]嘧啶-7-碳酰肼衍生物在内的N-稠合杂环化合物的高效直接合成。新的高效多米诺协议涉及一系列关键步骤，包括α,β-缩醛形成、Knoevenagel缩合、Michael反应、亚胺-烯胺互变异构和N-环化。这种无催化剂方法的优点在于其起始原料易于获得、操作简单、反应过程清洁、使用环境友好型溶剂以及对多种官能团具有耐受性。
