Synthesis and Antimicrobial Evaluation of Some New Organic Tellurium Compounds Based on Pyrazole Derivatives

A novel series of organic tellurium compounds based on pyrazole derivatives with a general formula of ArTeBr₃ and Ar₂TeBr₂ [Ar = 2-(3-(4-substituted phenyl)-5-(2-chlorophenyl)-1H-pyrazol-1-yl)-3,5-dinitrophenyl] were obtained by the refluxing of corresponding aryl mercuric chlorides with TeBr₄ in two different mole ratio of 1:1 and 2:1, respectively, in free-moisture dioxane solvent under an argon atmosphere. Compounds of ArTeBr₃ and Ar₂TeBr₂ were reduced by the action of ethanolic solution of hydrazine hydrate obtained Ar₂Te₂ and Ar₂Te, respectively. Reaction of Ar₂Te₂ with excess thionyl chloride or iodine gave the corresponding trihalides ArTeCl₃ and ArTeI₃, respectively while the reaction of Ar₂Te with thionyl chloride or iodine gave the corresponding Ar₂TeCl₃ and Ar₂TeI₃, respectively. The structures were elucidated according to their elemental analysis of carbon, hydrogen and nitrogen (CHN) and some of the spectroscopic techniques such as infrared IR and nuclear magnetic resonance for ¹H and ¹³C. The antimicrobial activity for all the synthetic compounds were assayed against both Gram-negative and Gram-positive bacteria by using the agar diffusion method. The tellurated pyrazole derivatives showed a good degree against bacteria growth. In some cases, the antimicrobial activities of the synthetic compounds were better than amoxicillin.