Synthesis, characterization, and inhibition effects of a novel eugenol derivative bearing pyrrole functionalities on the corrosion of mild steel in a HCl acid solution.

Semi-synthetic modifications of natural products have yielded numerous anti-cancer drugs, antimicrobials, and corrosion inhibitors. In this study, eugenol, a natural product, was synthetically modified to generate a novel heterocyclic compound: pyrrole, which forms crystals. The latter is the outcome of the condensation reaction between eugenol hydrazide and 2,5-hexanedione, conducted under reflux ethanol conditions, without a catalyst, achieving a 96% yield. This compound structure was characterized through spectroscopic methods, such as NMR and FTIR, and validated par the crystal's X-ray diffraction analysis. According to the findings of the electrochemical study, pyrrole demonstrated effective inhibition against the carbon steel's corrosion in a 1 M HCl acid solution.

1-Methyl-2-methyl-sulfanyl-6-nitro-1H-benzimidazole.

The mol-ecule of the title compound, C9H9N3O2S, is built up from fused five- and six-membered rings connected to methyl-sulfanyl and nitro groups, respectively. The mean plane through the fused ring system is inclined slightly relative to the plane passing through the nitro group [dihedral angle = 3.6 (2)°]. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and π-π inter-actions between imidazole rings [inter-centroid distance = 3.667 (3) Å], forming a three-dimensional network.