K. Bakhshi - Islamic Azad University Miyaneh Branch, Miyaneh, Iran
A. Jabbarpour - Islamic Azad University Miyaneh Branch, Miyaneh, Iran
Z. Moghaddami - Islamic Azad University Miyaneh Branch, Miyaneh, Iran

This work has done by experimentally methods [1, 2] and because of importance of Benzimidazole and quinoxaline derivates in biological systems we have made an effort to consider this case by theoretical studying with Gaussian 98 Code. In this work we have calculated the prediction of productive by HF, BLYP and B3LYP methods and 6- 31G,6-31G* and 6-31G** are used as basis sets. We have then compared our results to experimental results and there is good agreement between them. We calculated enthalpy reaction and Gibbs free energy and other thermodynamics properties to predict. We also used Hyper Chem Code to prepare our calculations in Gaussian Code.