title: Novel rearrangement of purines.
abstract: 6-Trichloromethyl-9-methylpurine (1) rearranges to 6-dichloromethyl-9-methyl-8-oxopurine (2) in aqueous mild acidic solution. The rearrangement is rationalized in terms of a reaction involving protonation, covalent hydration, prototropic equilibrium and/or a hydride transfer. An alternative mechanism involving a "positive' halogen compound and hypochlorous acid as an intermediary is also proposed. Compound 1 condenses with 4,5-diaminopyrimidine to give the purine-pyrimidine Schiff base pair 4.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D011687:Purines
chemical_list: D011687:Purines