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 ArTeBr(3) and Ar(2)TeBr(2) [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 TeBr(4) in two different mole ratio of 1:1 and 2:1, respectively, in free-moisture dioxane solvent under an argon atmosphere. Compounds of ArTeBr(3) and Ar(2)TeBr(2) were reduced by the action of ethanolic solution of hydrazine hydrate obtained Ar(2)Te(2) and Ar(2)Te, respectively. Reaction of Ar(2)Te(2) with excess thionyl chloride or iodine gave the corresponding trihalides ArTeCl(3) and ArTeI(3), respectively while the reaction of Ar(2)Te with thionyl chloride or iodine gave the corresponding Ar(2)TeCl(3) and Ar(2)TeI(3), 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 (1)H and (13)C. 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.