The Center for Chemical Research, Autonomous University of Morelos State, Av. Universidad 1001, Chamilpa, Cuernavaca 62210, Mexico.
Molecules. 2020 Oct 29;25(21):5008. doi: 10.3390/molecules25215008.
Singlet oxygen reactions produce 2-(-butyl)-4a-hydroperoxy-3-methyl-2,4a, 5,6,7,8-hexahydroquinazolin-4(3)-one quantitatively during diffusion crystallization of 2-(-butyl)-3-methyl-2,3,5,6,7,8-hexahydroquinazolin-4(1)-one in -hexane/CHCl solvent mixture. To confirm this photo-oxidation, a H-NMR study in CDCl was performed with exposure to ambient conditions (light and oxygen), with neither additional reactants nor catalysts. A theoretical study at the B3LyP/6311++G** level using the QST2 method of locating transition states suggests a two-step mechanism where the intermediate, which unexpectedly did not come from the peroxide intermediate, has a low activation energy.
在正己烷/CHCl 溶剂混合物中，2-（正丁基）-3-甲基-2,3,5,6,7,8-六氢喹唑啉-4(1)-酮的扩散结晶过程中，单线态氧反应定量生成 2-（正丁基）-4a-羟过氧基-3-甲基-2,4a,5,6,7,8-六氢喹唑啉-4(3)-酮。为了证实这种光氧化作用，在 CDCl 中进行了 H-NMR 研究，在暴露于环境条件（光和氧）下，既没有添加反应物也没有催化剂。使用 QST2 方法定位过渡态的 B3LyP/6311++G** 理论研究表明，该反应存在两步机制，其中出乎意料的是，中间体并非来自过氧化物中间体，具有较低的活化能。
