Utility of 4,6-dichloro-2-(methylthio)-5-nitropyrimidine. Part 3: Regioselective solid-phase synthesis of a 2,6,8,9-tetrasubstituted purine library
作者:Lars G.J. Hammarström、David B. Smith、Francisco X. Talamás
DOI:10.1016/j.tetlet.2007.02.104
日期:2007.4
regiocontrolled solid-phase synthesis of a 2,6,8,9-tetrasubstituted purine library was performed through on-resin elaboration of 4,6-dichloro-2-(methylthio)-5-nitropyrimidine. A series of primary amines were loaded on ArgoGel-MB-CHO resin via reductive amination to yield secondary amines. Subsequent attachment of the starting pyrimidine core unit and C6-chloride substitution by primary amines yielded the resin-bound
通过6,6-二氯-2-(甲硫基)-5-硝基嘧啶的树脂上精制,进行2,6,8,9-四取代嘌呤文库的第一个区域控制的固相合成。通过还原胺化将一系列伯胺负载在ArgoGel-MB-CHO树脂上,以产生仲胺。随后连接起始嘧啶核心单元和伯胺取代C6-氯化物,得到树脂结合的4,6-二取代-2-甲硫基5-硝基嘧啶。过硫酸氢钾® 2-甲硫部分与相应的砜的介导的氧化允许容易取代在2-位。氯化铬2协助还原硝基,然后进行酸催化的原酸酯环化,最后由TFA介导的裂解提供了四取代的嘌呤终产物。最终的大多数嘌呤均以良好至极佳的产率和纯度裂解,但是,发现N9的庞大基团阻碍了C8取代衍生物中的环化作用。对于这些系统,粗裂解产物的LC纯化可提供高纯度的目标嘌呤。