A new series of 1-[(E)-3-phenyl-2-propenyl]piperazine derivatives (5a-m) as antibacterial agents was designed and synthesized. The synthetic strategy was initiated by coupling different anilines (1a-m) with bromoacetyl bromide (2) in aqueous basic medium to acquire different electrophiles, 3a-m, with good yields. These electrophiles were further reacted with 1-[(E)-3-phenyl-2-propenyl]piperazine (4) to yield the desired compounds, N-(substituted)-2-{4-[(E)-3-phenyl-2-propenyl]-1-perazinyl}acetamides (5a-m). The structures of these compounds were established from their IR, 1H-NMR, 13C-NMR, EI-MS and CHN analysis data. The bacterial biofilm inhibitory potential of these piperazine derivatives was tested against two pathogenic strains, Bacillus subtilus and Escherichia coli. Two compounds, 5d and 5h were identified as suitable antibacterial agents. The cytotoxicity of these molecules was profiled through hemolytic assay and it was inferred that all the compounds were nearly harmless for membrane of red blood cells.

中文翻译：

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1-[（E）-3-苯基-2-丙烯基]哌嗪衍生物作为适度溶血性抗菌剂的合成及构效关系

设计并合成了一系列新的1-[（（E）-3-苯基-2-丙烯基]哌嗪衍生物（5a-m）作为抗菌剂。通过在水性碱性介质中将不同的苯胺（1a-m）与溴乙酰溴（2）偶联来启动合成策略，从而以高收率获得不同的亲电试剂3a-m。这些亲电子试剂与1-[（（E）-3-苯基-2-丙烯基]哌嗪（4）进一步反应，得到所需的化合物，N-（取代）-2- {4-[（E）-3-苯基] -2-丙烯基] -1-过嗪基}乙酰胺（5a-m）。这些化合物的结构由其IR，1H-NMR，13C-NMR，EI-MS和CHN分析数据确定。测试了这些哌嗪衍生物对两种致病菌株枯草芽孢杆菌和大肠杆菌的细菌生物膜抑制潜能。确定了两种化合物5d和5h是合适的抗菌剂。