Synthesis, Characterization and Anti-corrosion Activity of New Triazole, Thiadiazole and Thiazole Derivatives Containing Imidazo[۱,۲-a]pyrimidine Moiety

In this research, several heterocyclic rings (triazole, thiadiazol, thiazol) containing imidazo (۱,۲-a) pyrimidine moiety have been prepared via a series of reactions. To do this, synthesis of ۲-substituted imidazo (۱,۲-a) pyrimidine was performed by condensation of ۲-aminopyrimidine with (۴-bromo phenacyl bromide) or (۴-phenyl phenacyl bromide). Carbaldehyde group was prepared at position-۳ of ۲-substituted imidazo/pyrimidine rings by Vilsmeier-Haak reaction. Thiosemicarbazon derivatives (Schiff bases) were synthesized by condensation of ۳-carbaldehyde derivatives with thiosemicarbazide. Cyclization of thiosemicarbazone derivatives with Ac۲O, ۴-bromophenacyl bromide and HCl afforded the corresponding thiadiazole(diacetyl) derivatives, ۱,۳-thiazole derivatives and ۱,۲,۴-triazole derivatives respectively. Structures of the new derivatives were confirmed via FT-IR spectroscopy, some of which were confirmed via ۱H-NMR spectroscopy. Three of these new derivatives were evaluated by their anti-corrosion activity. 

Keywords:

imidazo/pyrimidine , Triazole , Thiadiazole , Thiazole , anti-corrosion