Microwave-assisted one-pot synthesis and performance test of novel thiadiazole derivatives as an inhibitor of oil transportation pipelines

This paper aims to improve the anti-corrosion of oil transportation pipelines.

The authors provide a simple, efficient and inexpensive one-pot method for the novel thiadiazole derivatives synthesized using 2-substituted [1, 3, 4] thiadiazole, P₂O₅ and chloroacetic acid as materials by using XH-200A computer microwave solid-liquid phase synthesizer. The results showed that microwave heating can finish the reaction sufficiently in 20 min, and the optimal addition reaction conditions were n([1, 3, 4] thiadiazole):n(chloroacetic acid):P₂O₅ = 1:1.2:1.3. Under such conditions, the yield of the title products was 54 per cent.

The structure of the title compounds were all confirmed by Fourier transform infrared spectroscopy and ¹H nuclear magnetic resonance spectroscopy. Water-based inhibitors corrosion behaviors on the stainless steel (SS) surface in 1 mol/L HCl solution at room temperature were also studied by weight loss methods and polarization curves. The results of the curves showed that an appropriate amount of 2a (40 ppm) can improve the anti-corrosion efficiency, whereas an excessive amount of 2a (e.g. 50 ppm) may not significantly increase the anti-corrosion efficiency.

In view of continuation of our studies, this paper presents microwave-assisted one-pot synthesis of 2-substitued [1, 3, 4] thiadiazole derivatives, and its anti-corrosion performance was tested by weight loss methods and polarization curves.