Synthesis, spectroscopic characterization, and prevention of carbon steel corrosion in hydrochloric acid of a new bis-isoxazoline-carvone

A series of C(3)-mono-substituted isoxazoline of type mono-and bis-isoxazoline, have been prepared from (R)-carvone 1 in a two-step procedure. First, (R)-carvone was treated with O-methoxy-benzaldoxime via a 1,3-dipolar cycloaddition reaction. The resulting mono-isoxazoline 2 was then converted into bis-isoxazoline(3), followed by an optimization study on the yield by varying the number of the equivalent of O-methoxy-benzaldoxime. The structures of mono-and bis-isoxazoline(3) newly synthesized were fully identified based on their HRMS and NMR spectral data. The bis-isoxazoline compound was used to evalu-ate the anticorrosion effect. The inhibitory properties of bis-isoxazoline-carvone(3) were evaluated using a variety of methods including weight loss(wl), electrochemical impedance spectroscopy (EIS), potentio-dynamic polarization (PDP), surface morphology analysis (SEM), quantum chemical calculations (DFT), and Monte Carlo simulation (MC). The results of (PDP) show that compound(3), which is a mixed type inhibitor, significantly reduces the corrosion rate of carbon steel (CS) through the creation of a protective film on the metal surface. According to EIS, SEM and theoretical studies, a bis-isoxazoline-carvone(3) is a better corrosion inhibitor with higher corrosion rates of about 92% at 298 K. The Langmuir isothermal model is the most appropriate to describe the adsorption of bis-isoxazoline-carvone(3) on the surface was mixed (chemisorption and physisorption).(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

A series of C(3)-mono-substituted isoxazoline compounds were prepared and evaluated for their anticorrosion effect, with the bis-isoxazoline-carvone compound showing significant reduction in the corrosion rate of carbon steel by forming a protective film on the metal surface.