This study focuses on synthesizing a new series of isoxazolinyl-1,2,3-triazolyl-[1,4]-benzoxazin-3-one derivatives 5a–5o. The synthesis method involves a double 1,3-dipolar cycloaddition reaction following a “click chemistry” approach, starting from the respective [1,4]-benzoxazin-3-ones. Additionally, the study aims to evaluate the antidiabetic potential of these newly synthesized compounds through in silico methods. This synthesis approach allows for the combination of three heterocyclic components: [1,4]-benzoxazin-3-one, 1,2,3-triazole, and isoxazoline, known for their diverse biological activities. The synthesis procedure involved a two-step process. Firstly, a 1,3-dipolar cycloaddition reaction was performed involving the propargylic moiety linked to the [1,4]-benzoxazin-3-one and the allylic azide. Secondly, a second cycloaddition reaction was conducted using the product from the first step, containing the allylic part and an oxime. The synthesized compounds were thoroughly characterized using spectroscopic methods, including ¹H NMR, ¹³C NMR, DEPT-135, and IR. This molecular docking method revealed a promising antidiabetic potential of the synthesized compounds, particularly against two key diabetes-related enzymes: pancreatic α-amylase, with the two synthetic molecules 5a and 5o showing the highest affinity values of 9.2 and 9.1 kcal/mol, respectively, and intestinal α-glucosidase, with the two synthetic molecules 5n and 5e showing the highest affinity values of −9.9 and −9.6 kcal/mol, respectively. Indeed, the synthesized compounds have shown significant potential as antidiabetic agents, as indicated by molecular docking studies against the enzymes α-amylase and α-glucosidase. Additionally, ADME analyses have revealed that all the synthetic compounds examined in our study demonstrate high intestinal absorption, meet Lipinski’s criteria, and fall within the required range for oral bioavailability, indicating their potential suitability for oral drug development.

Benzimidazole derivatives are widely used as a drug. In this work, we valorized the electrochemical activities of our new Benzimidazole-derived compound, 2-(4-chlorophenyl)-4-nitro-1H-benzimidazole (OS1), as a green inhibitor that can be used in environmental applications, which gives rise to a tautomeric equilibrium (A and B), applied to mild steel in a 1 M HCl solution. The inhibitory effect of 2-(4-chlorophenyl)-4-nitro-1H-benzimidazole (OS1) on carbon steel (CS) corrosion in 1 M HCl was evaluated with DFT studies. The value ΔN = 0.019 for A and 0.057 is positive and less than 3.6, indicating that the molecule functions as an electron donor towards the iron substrate, creating a shielding layer that prevents corrosion. DFT results identified the nucleophilic that C(4,6,24) N(12) O(15) and Cl(27) in A and C(4,5,6,32) O(14,15) and Cl(26) in B and electrophilic C(6) N(12) and O(15) in A and O(14,15) in B attack sites. Notably, these findings established that Tautomer A is the most stable.