Razavi Zohreh Sahhaf, Bayat Mohammad, Hosseini Hajar
Department of Chemistry, Faculty of Science, Imam Khomeini International University Qazvin Iran
RSC Adv. 2020 Aug 21;10(52):31039-31048. doi: 10.1039/d0ra03910a.
A highly efficient and straightforward synthesis of N-fused heterocyclic compounds including 5-amino-7-(aryl)-8-nitro-'-(1-(aryl)ethylidene)-3,7-dihydro-2-thiazolo[3,2-]pyridine-6-carbohydrazide derivatives is successfully achieved a five-component cascade reaction utilizing cyanoacetohydrazide, various acetophenones, aromatic aldehydes, 1,1-bis(methylthio)-2-nitroethylene and cysteamine hydrochloride in ethanol at reflux conditions. The new approach involves domino ,-acetal formation, Knoevenagel condensation, Michael reaction, imine-enamine tautomerization and -cyclization sequences. The prominent advantages of this protocol include: facility of operation, available and economical starting materials, no need for toxic solvents, high yields and tolerance of a wide variety of functional groups.
通过在乙醇中回流条件下利用氰基乙酰肼、各种苯乙酮、芳香醛、1,1-双（甲硫基）-2-硝基乙烯和盐酸半胱胺进行五组分串联反应，成功实现了包括5-氨基-7-（芳基）-8-硝基-'-(1-（芳基）亚乙基）-3,7-二氢-2-噻唑并[3,2-]吡啶-6-碳酰肼衍生物在内的N-稠合杂环化合物的高效直接合成。新方法涉及多米诺α-缩醛形成、克诺文纳格尔缩合、迈克尔反应、亚胺-烯胺互变异构和环化序列。该方案的突出优点包括：操作简便、起始原料易得且经济、无需使用有毒溶剂、产率高以及对多种官能团具有耐受性。
