Unveiling the synthesis and spectral characterizations of novel (E)-furan-2-yl acrylohydrazides: an exploration in molecular design

Abstract

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) acrylohydrazide (3) with diverse benzaldehyde and acetophenone derivatives. Comprehensive characterization of the synthesized compounds was achieved through 1D nuclear magnetic resonance spectroscopic analyses (1H and 13C NMR), 2D nuclear magnetic resonance 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), Notably, compounds 4a and 4b predominantly adopted the sp E conformer (Ec=c sp EC=N), while the remaining compounds (4c–h), favored the antiperiplanar conformation (Ec=c ap EC=N) even if for the 4g compound it was challenging to determine the EC=N conformer. These findings contribute valuable insights into the conformational dynamics of this class of compounds, holding significance for applications in diverse scientific domains.