In this study, we present the synthesis of novel derivatives of 3-furan-2-yl acrylohydrazide using a meticulous three-step reaction sequence. The synthesis ends up in the condensation of (E)-3-(furan-2-yl) acrylohydrazine (3) with diverse benzaldehyde and acetophenone derivatives. Comprehensive characterization of the synthesized compounds was achieved through 1D NMR spectroscopic analyses (1H and 13C NMR), 2D NMR spectroscopy (HSQC, NOESY), and high-resolution mass spectrometry (HRMS). The investigation of 1H NMR data at room temperature in deuterated dimethyl sulfoxide (DMSO-d6) unveiled the existence of (E)-3-(furan-2-yl) acrylohydrazide derivatives (4a-h) in a conformational equilibrium, manifesting as a mixture of synperiplanar E (sp E) and antiperiplanar E (ap E), or synperiplanar Z (sp Z) and antiperiplanar Z (ap Z). Notably, compounds 4a and 4b predominantly adopted the sp E conformer (Ec=c sp EC=N), while compounds 4c and 4d favored the antiperiplanar conformation. For the remaining compounds (4e-h), both conformers were nearly equimolar, with a marginal preference for the anti over the syn conformer. Interestingly, compounds 4f and 4h exhibited a prevalence of the apZ conformer (Ec=c ap ZC=N), while compound 4e featured the apE conformer (Ec=c ap EC=N). UV-visible absorption spectra for the N-acylhydrazones (4a-h) indicated absorption within the 570-635 nm range. Furthermore, cyclic voltammetry results demonstrated the capacity of the synthesized (E)-3-(furan-2-yl) acrylohydrazide derivatives (4a-h) to undergo quasi-reversible oxidation and reduction processes on a platinum electrode. These findings contribute valuable insights into the conformational dynamics and electrochemical behavior of this class of compounds, holding significance for applications in diverse scientific and technological domains.

中文翻译：

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揭示新型 (E)-呋喃-2-基丙烯酰肼的合成、光谱表征和电化学潜力：分子设计的探索

在这项研究中，我们采用细致的三步反应顺序合成了 3-呋喃-2-基丙烯酰肼的新型衍生物。合成最终导致 (E)-3-(呋喃-2-基) 丙烯酰肼 (3) 与多种苯甲醛和苯乙酮衍生物缩合。通过 1D NMR 光谱分析（1H 和 13C NMR）、2D NMR 光谱（HSQC、NOESY）和高分辨率质谱（HRMS）对合成化合物进行了全面表征。室温下氘化二甲亚砜 (DMSO-d6) 中的 1H NMR 数据研究揭示了处于构象平衡的 (E)-3-(呋喃-2-基)丙烯酰肼衍生物 (4a-h) 的存在，表现为共围平面 E (sp E) 和反围平面 E (ap E) 的混合物，或共围平面 Z (sp Z) 和反围平面 Z (ap Z)。值得注意的是，化合物4a和4b主要采用sp E构象（Ec=c sp EC=N），而化合物4c和4d则倾向于反围平面构象。对于其余化合物 (4e-h)，两种构象异构体几乎等摩尔，反式构象异构体略优于顺式构象异构体。有趣的是，化合物 4f 和 4h 普遍存在 apZ 构象异构体 (Ec=c ap ZC=N)，而化合物 4e 则具有 apE 构象异构体 (Ec=c ap EC=N)。N-酰基腙 (4a-h) 的紫外-可见吸收光谱表明在 570-635 nm 范围内有吸收。此外，循环伏安法结果表明，合成的(E)-3-(呋喃-2-基)丙烯酰肼衍生物(4a-h)能够在铂电极上进行准可逆氧化和还原过程。这些发现为此类化合物的构象动力学和电化学行为提供了宝贵的见解，对于不同科学和技术领域的应用具有重要意义。