Zhao Di, Liu Yanying, Li Yang, Chen Yu
College of Chemistry and Chemical Engineering, Bohai University Jinzhou 121013 China
Research Institute of Jinzhou Petrochemical Company Jinzhou 121013 China.
RSC Adv. 2022 Aug 9;12(34):22054-22059. doi: 10.1039/d2ra04587g. eCollection 2022 Aug 4.
In this work, a green Hantzsch synthesis of 4-ferrocenylthiazole derivatives has been accomplished successfully. The Hantzsch reaction between bromoacetylferrocene and various aryl thioureas, 1-alkylindole-3- or 9-alkylcarbazole-3-carbothioamides proceeded efficiently in a deep eutectic solvent (DES) that is, choline chloride/glycerol (ChCl/Gly) (1 : 2 molar ratio) at 80 °C, avoiding the use of common volatile organic solvents. Moreover, the DES media could be reused up to three times without any appreciable decrease in the yield. The synthetic strategy has the attractive features such as mild and environmentally benign reaction conditions, experimental simplicity, easy work-up procedure and good yields. Subsequently, a preliminary screening for antibacterial activities of all these newly-synthesized compounds revealed that the halo-substituted (F, Cl, Br) compounds 3f-h showed significant antibacterial activities against Gram (+) bacterial and Gram (-) , among which the fluoro-substituted 3f possessed the best activity with the MIC value of 7.8125 μg mL, being higher than the reference drug ciprofoxacin (15.625 μg mL).
在本工作中，已成功完成了4-二茂铁基噻唑衍生物的绿色汉茨希合成。溴乙酰基二茂铁与各种芳基硫脲、1-烷基吲哚-3-或9-烷基咔唑-3-碳硫酰胺之间的汉茨希反应在深共熔溶剂（DES），即氯化胆碱/甘油（ChCl/Gly）（摩尔比1∶2）中于80℃高效进行，避免了使用常见的挥发性有机溶剂。此外，DES介质可重复使用多达三次，产率没有任何明显下降。该合成策略具有温和且环境友好的反应条件、实验简单、后处理程序简便以及产率良好等吸引人的特点。随后，对所有这些新合成化合物的抗菌活性进行的初步筛选表明，卤代（F、Cl、Br）化合物3f - h对革兰氏阳性菌和革兰氏阴性菌均表现出显著的抗菌活性，其中氟代的3f活性最佳，MIC值为7.8125 μg/mL，高于参比药物环丙沙星（15.625 μg/mL）。
