New synthetic approaches to condensed pyridazinones: alkylpyridazinyl carbonitriles as building blocks for the synthesis of condensed pyridazinones
作者:Hanan Al-Awadhi、Fatima Al-Omran、Mohamed H. Elnagdi、Lourdes Infantes、Conceptión Foces-Foces、Nadine Jagerovic、José Elguero
DOI:10.1016/0040-4020(95)00829-w
日期:1995.11
same product was obtained from the reaction of the amide 3g with formaldehyde in refluxing pyridine. The reaction of 3a, c with arylidenemalononitrile (23a, b) gives the tetrahydrophthalazines 25a-c. The pyridazin-4-ones 26a-d were prepared from the reaction of 2a-d with dimethylformamide dimethylacetal in refluxing dioxane. The crystal and molecular structure of compound 18a was solved by X-ray analysis
通过将芳基hydr2a-d与氰基乙酸乙酯缩合来制备哒嗪基-5-腈(3a-d)。2a与丙二腈的类似缩合得到吡啶并[2,3-c]哒嗪衍生物(8)。在三乙胺的存在下,化合物3a-d在回流的乙醇溶液中与元素硫反应,生成噻吩并[3,4- d ]吡啶并酮9a-d。通过使9e与富马酸二乙酯反应来制备1,3,4-噻二氮杂ena啶12。相反,从13a-c与9e的反应仅生成了酞嗪14a-c。化合物9a-c与丙烯腈反应,得到1,3,4-噻二氮ac庚烷18a,b。化合物将3a与苯甲醛缩合,得到19a。3a,c,d与二甲基甲酰胺二甲基缩醛的缩合得到19b-d。当在乙酸铵存在下在乙酸中回流时,化合物19b环化为20b。从酰胺3g与甲醛在回流的吡啶中的反应获得相同的产物。的反应图3a,C与arylidenemalononitrile(23A,B),得到tetrahydrophthalazines 25A-C 。由2a-d反应制备哒嗪-4-酮26a