Regioselective synthesis of multi‐functionalized benzopyranophenazine derivatives: Comparative studies on corrosion inhibition efficiency on mild steel in <scp>1M H₂SO₄</scp> solution

Abstract Objectives A regioselective approach has been developed for the synthesis of benzopyranophenazine derivatives using In (OTf)3 as a catalyst in one‐pot synthesis. Further, these synthesized compounds were successfully used organic corrosion inhibitors on mild steel 1M H2SO4 solution. Methods The confirmed NMR, and HRMS their regioselectivity was by DFT studies B3LYP/6‐31G (d, p) basis set. corrosion, inhibition efficiencies various methods such weight loss technique, electrochemical impedance spectroscopy, potentiodynamic polarization studies. Results two MBPPand BBPP show excellent properties than previously reported inhibitors, especially, electron‐donating nature methoxy‐substituted phenazine superior 98.96 900 ppm electron withdrawing bromo substituted derivative same concentration which indicates that electronic structure inhibitor plays an important role efficiency acid medium. Conclusion compound efficiently inhibits surface it forms barrier metal surface. As result, both MBPP act very effective shows more inhibitors.