Synthesis of 8-arylsulfoxyl/sulfonyl adenines

We report a method for the synthesis of 9-N-alkyl-8-arylsulfoxyl adenines and 9-N-alkyl-8-arylsulfonyl adenines. The approach starts with a tandem one-pot reaction that by using Mitsunobu conditions converts 8-arylsulfanyl adenines to the corresponding iminophosphorane protected 9-N-alkyl-8-arylsulfanyl adenines. These compounds were further subjected to selective OXONE®/alumina mediated oxidation followed by deprotection of the amine leading to the desired sulfoxides and sulfones.