Novel and Improved Method for the Synthesis of Bis-Benzimidazole, Bis-Benzoxazole, and Bis-Benzothiazole Derivatives

Eleven novel derivatives belonging to the benzimidazole, benzoxazole, and benzothiazole families were successfully synthesized through a condensation reaction involving ophenylenediamine, o-aminothiophenol, and o-aminophenol, respectively. These reactions were carried out in the presence of cyclohexanediaminetetraacetic acid (CDTA) under acidic conditions, which acted as a catalyst to promote the cyclization process. The synthetic procedures employed represent innovative methodologies for the preparation of bis-benzimidazole, bis-benzoxazole, and bisbenzothiazole derivatives, offering isolated yields ranging from 50% to 70%, depending on the specific substrate and reaction conditions. The structural identity and chemical composition of the synthesized compounds were rigorously confirmed by a combination of advanced spectroscopic techniques. These included Nuclear Magnetic Resonance (NMR) spectroscopy, providing detailed information about the hydrogen and carbon environments within the molecules, Fourier-Transform Infrared (FTIR) spectroscopy, allowing for the identification of characteristic functional groups, and High- Resolution Mass Spectrometry (HRMS), offering precise molecular weight determination and providing structural insights. Furthermore, a plausible interaction mechanism underlying the formation of these heterocyclic compounds was proposed, contributing to a better understanding of the reactivity and synthetic pathway involved. This study highlights the potential of CDTA as an effective mediator in heterocyclic synthesis, laying the groundwork for the future development of related compounds with potential applications in medicinal or materials chemistry.