4,6-二羟基嘧啶的合成热力学分析

THERMODYNAMIC ANALYSIS FOR THE SYNTHESIS OF 4,6-DIHYDROXY PYRIMIDINE

采用Benson和Joback基团贡献法,对丙二酸二甲酯和甲酰胺在甲醇钠溶液中制备4,6-二羟基嘧啶的过程的反应焓变ΔrHΘ、反应熵变ΔrSΘ、反应吉布斯自由能变ΔrGΘ及其平衡常数Kp进行了热力学估算。结果表明:ΔrHΘ>0,反应为吸热反应;ΔrGΘ<0,此反应过程为自发过程;Kp随着温度的升高而增大。

The reaction heat , reaction entropy changeArS@ , Gibbs free energy changeArG@ and equilibrium constants Kp for the synthesis of 4,6-dihydroxy pyrimidine by reaction of dimethyl mal- onate and formamide in sodium methoxide-methanol solution were calculated by Benson and Joback group contribution methods. The results show that the reaction is endothermic,〉0 and is spon- taneous,ArGed0; Kp increases with increasing temperature. The relevant thermodynamic reference datas are provided for the further research and industrial production of synthesis of 4,6-dihydroxy-py- rimidine.