作者:Ángel Díaz-Ortiz、José Elguero、Concepción Foces-Foces、Antonio de la Hoz、Andrés Moreno、María del Carmen Mateo、Ana Sánchez-Migallón、Gema Valiente
DOI:10.1039/b315956f
日期:——
2,4-Diamino-1,3,5-triazines have been prepared by reaction of dicyandiamide with nitriles under microwave irradiation, a method that can be considered as a green procedure due to the reduction in the use of solvents during synthesis and purification, the short reaction time and the simplicity of the procedure. The structures have been confirmed in solution by NMR spectroscopy. Variable temperature experiments have been used to calculate the free energy of activation for rotation about the amino–triazine bond. The crystal structures of three 2,4-diamino-6-R-1,3,5-triazine derivatives (3a: R = phenyl, 3i: R = 1-piperidino and 3g: R = 1-phenylpyrazol-3-yl) have been determined by X-ray analysis. The N–H⋯N interactions change from structure to structure, resulting in a variation from pseudo-honeycomb networks to corrugated rosette layers.
2,4-二氨基-1,3,5-三嗪是通过在微波照射下将二氰胺与腈类反应制备的,这种方法可以被视为一种绿色程序,因为在合成和纯化过程中减少了溶剂的使用,反应时间短且过程简单。通过NMR光谱在溶液中确认了其结构。可变温度实验用于计算关于氨基-三嗪键旋转的活化自由能。三种2,4-二氨基-6-R-1,3,5-三嗪衍生物(3a: R=苯基, 3i: R=1-哌啶基和3g: R=1-苯基吡唑-3-基)的晶体结构已通过X射线分析确定。N–H⋯N相互作用因结构的不同而变化,导致从伪蜂窝网络到波纹玫瑰层的变化。