Facile synthesis of 6-cyano-9-substituted-9H-purines and their ring expansion to 8-(arylamino)-4-imino-3-methylpyrimidino-[5,4-d]pyrimidines

Article abstract of DOI:10.1039/b106539b

6-Cyano-9-substituted-9H-purines were prepared in a high yielding, one-step process by refluxing triethyl orthoformate or triethyl orthopropionate with the corresponding (Z)-N₁-(aryl- or benzyl)-N₂-(2-amino-1,2-dicyanovinyl)formamidi