Syntheses of Polymers and Oligomers Having Adenine Derivatives

9-(2′,3′-Dihydroxyethyl)-8-bromoadenine was synthesized by the reaction of 9-(2′,3′-dihydroxyethyl)-adenine with bromine. The reaction of 9-(2′,3′-dihydroxyethyl)-8-bromoadenine with phosphorus oxychloride in trimethyl phosphate produced 9-(2′,3′-dihydroxypropyl)-8-bromoadenine-3′-phosphate. The condensation polymerization of 9-(2′,3′-dihydroxypropyI)-8-bromoadenine-3′-phosphate was conducted in refluxing dimethylformamide-water (9:1) using dicyclohexylcarbodiimide as a dehydrating agent. The oligomer obtained is soluble in water and has a molecular weight of more than 1000 according to gel-filtration measurement. This oligomer showed hypochromicity of 3°, with denatured yeast RNA. The condensation polymerization of 9(2′,3′-dihydroxypropyl)-8-bromoadenine-3′ -phosphate was also carried out using imidazole or a triethylamine-hydrochloric acid system.