Abstract Reaction of 6-amino-2-methylthio-3-methyluracil with ethyl ethoxymethyleneoxaloacetate or methyl(Z)-2-acetylamino-3-dimethylaminopropenoates afforded diethyl 2-(1,6-dihydro-1-methyl-2-(methylthio)-6-oxopyrimidin-4-yl-amino)methylene malonate or (2E)-methyl 3-(1,6-dihydro-1-methyl-2-(methylthio)-6-oxopyrimidin-4-yl-amino)-2-acetamidoacrylate, respectively. Cyclization of each of the latter products by sodium ethoxide afforded new pyrido [2,3-d]pyrimidines, which were ribosylated with 1-O-acetyl-2,3,5-O-benzoyl-β-D-ribofuranose by the silylation method yielded the protected nucleosides. The protected nucleosides were debenzoylated by sodium methoxide to afford novel pyrido[2,3-d]pyrimidine nucleosides. The structural assignmentsv for the new compounds were based on their elemental analysis and spectroscopic data.

中文翻译：

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核苷 11：合成吡啶并[2,3-d]嘧啶及其核苷的新衍生物

摘要 6-氨基-2-甲硫基-3-甲基尿嘧啶与乙氧基亚甲基草酰乙酸乙酯或(Z)-2-乙酰氨基-3-二甲氨基丙烯酸甲酯反应得到2-(1,6-二氢-1-甲基-2-(甲硫基)二乙酯) -6-oxopyrimidin-4-yl-amino)methylene丙二酸酯或 (2E)-methyl 3-(1,6-dihydro-1-methyl-2-(methylthio)-6-oxopyrimidin-4-yl-amino)-2 -乙酰氨基丙烯酸酯，分别。后一种产物中的每一种被乙醇钠环化得到新的吡啶并 [2,3-d] 嘧啶，它们通过甲硅烷基化作用与 1-O-乙酰基-2,3,5-O-苯甲酰基-β-D-呋喃核糖进行核糖基化方法产生受保护的核苷。受保护的核苷通过甲醇钠脱苯甲酰化，得到新型吡啶并[2,3-d]嘧啶核苷。新化合物的结构归属基于它们的元素分析和光谱数据。