Semi-Empirical Computation on Mechanism of Imidazolines and Benzimidazoles Synthesis and Their QSAR Studies
作者:Swapnali Hazarika、Dilip Konwar、Manas Jyoti Bora
DOI:10.14233/ajchem.2014.16320
日期:——
A green, mild and anaerobic synthesis of imidazolines and benzimidazoles from aldehydes and diamines using I2/KI/K2CO3/H2O system has been investigated by semi-empirical methods. The observed efficient direction of the above synthesis has been modeled from a comparison of the energies of four possible transition states arising from mono and di additions of iodines in the configured molecules. In the reaction I1 B is the most favorable transition state [TS] which is shown to be 20 Kcal/mol by PM3 analyses. The resulting trends of relative transition states energies are in excellent agreement with the experimental observations. Also, the bond order, bond length, heat of formation is in good agreement to the formation of product B. In order to establish the suitable mechanism of the reaction a quantitative structure activity relationship analysis has been made using hydrophobicity as the molecular descriptor. In this analysis the values of refractivity, polarizability, hydration energy, electron affinity, ionization potential and dipole moment of the compounds have been correlated with their hydrophobicity which has been taken as the molecular property.
通过半经验方法研究了在I2/KI/K2CO3/H2O体系下,使用醛和二胺进行绿色、温和且厌氧的咪唑啉和苯并咪唑合成。通过比较四种可能的过渡状态的能量——源自配置分子中单加和双加碘——来模拟上述合成的高效方向。在反应I1中,B是最佳过渡态[TS],PM3分析显示其能量为20千卡/摩尔。相对过渡态能量的趋势与实验观察结果非常吻合。此外,键级、键长和生成热都与产物B的生成一致。为了确定反应的适宜机理,使用疏水性作为分子描述符进行了定量结构活性关系分析。在此分析中,化合物折射率、极化率、水合能、电子亲和力、电离势和偶极矩的值与其疏水性相关联,作为分子属性。