Purines XIV. [1]. Reactivity of 8-Bromo-3,9-dimethylxanthine Towards Some Nucleophilic Reagents

Article abstract of DOI:10.1002/jhet.5570350428

The reactivity of 8-bromo-3,9-dimethylxanthine (6) towards a variety of nucleophilic reagents has been investigated. Nucleophilic displacements take place easily with aliphatic mercaptans and aliphatic alcohols, whereas aliphatic amines required more severe conditions. Prolonged heating of 6 with amines causes a new type of rearrangement from 3,9- to 3,7-dimethylxanthines due to a 1,3-sigmatropic shift of the N(9)-methyl group.