In this study, Heterocyclic Compounds were synthesized by several steps as following:
First step: the 1-[4-(5-Bromo-pentyloxy)-phenyl]-ethanone (B1) was synthesized by treatment of 4-hydroxyacetophenon (A) with 1,5-dibromo pentane in presence of anhydrous potassium carbonate and acetone.
Second step: the 2-(4-Acetyl-phenoxy)-1-(4-bromo-phenyl)-ethanone (B2) was synthesized by treatment of 4-hydroxyacetophenon (A) with of 4-bromolphenacylbromide in presence of anhydrous potassium carbonate and acetone.
Third step: Chalcon derivatives (C1-C6) were synthesized by aldol-condensation between (B1, B2) compounds with various aldehydes
Fourth step: pyrazole derivatives (D1-D10) and (D16- D17) compounds were synthesized by reaction of Chalcon derivatives (C1-C6) with appropriate hydrazine (hydrazine hydrate, phenyl hydrazine).
Fifth step: pyrimidine derivatives (D11-D14) and (D18- D19) compounds were synthesized by reaction of Chalcon derivatives (C1-C6) with appropriate (urea, Thiourea).
Sixth step: isoxazol derivatives (D15) and (D20) compounds were synthesized by reaction of Chalcon derivatives (C5) and (C6) with Hydroxylamine-hydrochloric.
The prepared compounds were characterized by using FT-IR, 1H-NMR, 13C-NMR spectroscopic techniques, CHNO-S element analysis techniques and melting point device for some of them.The prepared compounds (D1-D20) were used as corrosion inhibitors for mild steel in 1M H2SO4 at 30 C for 24 h. Weight loss measurement was regarded as evaluation method to test the inhibition efficiency of the above compounds. Gibbs free energy values are calculated for the adsorption was obtained useful information to predict the interaction between organic compounds molecules and the metal surface as corrosion inhibitors for the metal surface.
