The psuedo-michael reaction of 2-aminoimidazolines 2. Part 1. Synthesis and structure assignment of isomeric 5(1<i>H</i>)-Oxo and 7(1<i>H</i>)-Oxo-2,3-dihydroimidazo[1,2-<i>a</i>]pyrimidine-6-carboxylates
作者:Dariusz Matosiuk、Kalevi Pihlaja、Vladimir V. Ovcharenko、Izabela Dybała、Anna E. Kozioł、Maria Gdaniec、Halina Szumiło、Zbigniew Karczmarzyk
DOI:10.1002/jhet.5570400112
日期:2003.1
yielded mixtures, with varying ratio, of isomeric 1-aryl-7(1H)-oxo- (4a-4f) and 1-aryl-5(1H)-oxo-2,3-dihydroimidazo[1,2-a]pyrimidine-6-carboxylates (5a-5f). The molecular structure of selected isomers, 4b and 5c, was confirmed by X-ray crystallography. Frontal chro-matography with delivery from the edge was applied for the separation of the isomeric esters. The isomer ratio of the reaction products depended
研究了1-芳基-2-氨基咪唑啉-2与乙氧基亚甲基丙二酸二乙酯(DEEM)的拟迈克尔反应。进行了广泛的结构研究,以确认反应过程。对于具有N 1个芳族取代基的衍生物,发现反应过程与温度有关。当反应温度保持在-10℃时,仅形成1-芳基-7(1H)-氧代-2,3-二氢咪唑-偶氮[1,2 - a ]嘧啶-6-羧酸盐(4)。与先前的建议相反。在室温条件下,相同的反应会生成不同比例的异构体1-芳基-7(1 H)-氧代-(4a-4f)和1-芳基-5(1 H)-氧代-2的混合物, 3-二氢咪唑[1,2-a ]嘧啶-6-羧酸盐(5a-5f)。通过X射线晶体学证实了所选异构体4b和5c的分子结构。从边缘输送的正面色谱用于分离异构体酯。反应产物的异构体比例取决于苯环上取代基的特性。所述1-芳基7(1 ħ) -氧代羧酸盐(4A-4F当苯环含有H,4-CH)是优选3,4-OCH 3和3,4-二氯2个的取代基。苯环中3