A novel approach to the synthesis of (purin-6-yl)acetates was developed based on Pd-catalyzed cross-coupling reactions of 6-chloropurines with a Reformatsky reagent. Their reduction with NaBH4 and treatment with MnO2 gave 6-(2-hydroxyethyl)purines, while reactions with amines in presence of NaCN afforded 6-(carbamoylmethyl)purines. Mesylation of the 6-(2-hydroxyethyl)purines followed by nucleophilic substitutions gave rise to several 6-(2-substituted ethyl)purines. This methodology was successfully applied to the synthesis of substituted purine bases and nucleosides for cytostatic and antiviral activity screening. None of the compounds exerted significant activity.
基于Pd催化的
6-氯嘌呤与Reformatsky试剂的交叉偶联反应,开发了一种合成(purin-6-yl)
乙酸酯的新方法。它们经过NaBH
4还原和MnO
2处理后,形成6-(2-羟乙基)
嘌呤,而与胺在NaCN存在下反应则得到6-(carbamoylmethyl)
嘌呤。6-(2-羟乙基)
嘌呤的Mesylation后,进行亲核取代反应,可以得到多种6-(2-取代乙基)
嘌呤。这种方法成功地应用于合成替代
嘌呤碱基和核苷,用于细胞毒和抗病毒活性筛选。但是,这些化合物均未表现出显著的活性。