Selective cyclization of S‐substituted pyrimidinethione: Synthesis and antimicrobial evaluation of novel polysubstituted thiazolopyrimidine and thiazolodipyrimidine derivatives
作者:Hayat E. Alzahrani、Ahmed M. Fouda、Ayman M. S. Youssef
DOI:10.1002/jccs.201900199
日期:2020.5
chloroacetonitrile, and phenacyl bromide to give the corresponding S‐substituted derivatives Va–c. Treatment of IVa–c with ethyl bromoacetate in ethanol under reflux in the presence of potassium hydroxide solution led to the formation of N‐(4‐chlorophenyl)‐7‐methyl‐3‐oxo‐5‐(aryl)‐2,3‐dihydro‐5H‐thiazolo[3,2‐a]pyrimidine‐6‐carboxamide derivative VIII a–c in a single‐step synthesis. On the other hand, compound
合成策略基于4-芳基-N-(4-氯苯基)-6-甲基-2-硫代-1,2,3,4-四氢嘧啶-5-羧酰胺衍生物IV a-g与一些烷基的烷基化卤化物和α-卤代酮,即甲基碘,氯乙腈和苯甲酰溴,得到相应的S-取代的衍生物Va-c。在氢氧化钾溶液的存在下,在回流下用乙醇中的溴乙酸乙酯处理IVa–c,导致形成N‐(4-氯苯基)‐7‐甲基‐3‐氧代‐5‐(芳基)‐2,3‐3单步合成中的二氢-5H-噻唑并[3,2-a]嘧啶-6-羧酰胺衍生物VIII a-c。另一方面,化合物IVa与α-卤代腈,即氯乙腈和一溴丙二腈反应,分别直接生成噻唑并[3,2-a]嘧啶衍生物Xa和Xb,化合物Xb也分别与甲酸,甲酰胺和硫氰酸铵反应分别形成噻唑二嘧啶衍生物XI-XIII。化合物VIIIa–c与吡啶中的壬二唑鎓盐偶联,得到相应的2-芳基azo唑衍生物XVIa–e。化合物IV a–g和VIIIa–c在微波辐射下重新合成。测试了一些新合成的化合物的抗菌活性。