Malononitrile purines

CyanomethyIene)purine derivatives can be prepared by reaction of the sodium salt of an activated cyanomethylene compound such as malononitrile, a-cyanoacetamide, and ethyl cyanoacetate with 6-halogenated or-methylsulfonated purine derivatives, e.g. formation of 2 and 3. ... 

The 5-azido-4-cyanoimidazole (295) and malononitrile reacted to give [l,2,3]tri-azolo[5,1-/>]purine-3-carbonitrile 296 (95JHC457) (Scheme 86). 

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