3-Aryl-1-benzoylthioureas with α-bromoketones in Water form 2-N-benzoyl-3-arylthiazol-2(3H)-imines, not 3-aryl-1-benzoylimidazoline-2-thiones
作者:C.B. Singh、Siva Murru、Veerababurao Kavala、Bhisma K. Patel
DOI:10.3184/030823407x196719
日期:2007.3
The products obtained by the reaction of 1-benzoyl-3-phenylthioureas with α-bromoketones in water in the presence of triethylamine are not imidazoline-2-thiones as reported (J. Chem. Res. 2005, 689–690); rather they are thiazol-2-imine derivatives.
It Is “Thiazolidene-2-imine” and Not Imidazole-2-thione as the Reaction Product of 1-Benzoyl-3-phenylthiourea with Br<sub>2</sub>/Enolizable Ketone
作者:C. B. Singh、Siva Murru、Veerababurao Kavala、Bhisma K. Patel
DOI:10.1021/ol062371b
日期:2006.11.9
[GRAPHICS]The products obtained by the reaction of benzoyl-3-phenylthioureas with bromine and enolizable ketones in the presence of triethylamine are not imidazole-2-thione derivatives as reported (Org. Lett. 2003, 5, 1657 - 1659) rather they are thiazolidene-2-imine derivatives.
A convenient one-pot synthesis of thiazol-2-imines: application in the construction of pifithrin analogues
作者:Siva Murru、C.B. Singh、Veerababurao Kavala、Bhisma K. Patel
DOI:10.1016/j.tet.2007.11.076
日期:2008.2
3-disubstituted thioureas using 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT). Unsymmetrical 1,3-disubstituted thioureas give regioselective products with symmetrical ketones, which are mainly governed by the pKas of NH protons of thiourea, whereas symmetrical 1,3-disubstituted thioureas give regioselective products with symmetrical carbonyl compounds owing to the regioselective bromination of
首次分离出反应中间体,从而进一步了解了噻唑-2-亚胺的形成机理。反应的第一步需要碱性介质,而第二步是酸介导的E1消除反应。通过使用1,1'-(乙烷-1,2-二基)双吡啶鎓溴化吡啶鎓(EDPBT)将羰基化合物与硫脲和1,3-二取代的硫脲缩合,已实现了有效的一锅合成取代的噻唑-2-亚胺。 )。不对称的1,3-二取代的硫脲会产生带有对称酮的区域选择性产物,该酮主要由p K a决定。s的是硫脲的NH质子,而对称的1,3-二取代的硫脲由于酮的区域选择性溴化作用而产生具有对称羰基化合物的区域选择性产物。该方法已扩展为在较短的反应时间内以高收率获得新型神经退行性药物候选品菲丝菌素-α类似物。该方法简单,通用,可用于不同的1,3-二取代的硫脲以及一系列羰基化合物。