Pyrrolopyrimidine nucleosides. XIII. Synthesis and chemical reactivity of certain selenopyrrolo[2,3-d]pyrimidine nucleosides

5-Cyano-7-(β-D-ribofuranosyl)pyrrolo2,3-d]pyrimidin-4-selone ( 1 ) has been prepared via a reaction of the appropriate 4-chloro compound with sodium hydrogen selenide. Alkylation of 2 under basic conditions has provided certain 4-substitutedseleno-5-cyano-7-(β-D-ribofuranosyl)-pyrrolo2,3-d]pyrimidines. 5-Cyano-4-methylseleno-7-(β-D-ribofuranosyl)pyrrolo2,3-d]pyrimidine was allowed to react with hydroxylamine and hydrazine. The products obtained and reaction course were compared to those obtained from identical reactions using the corresponding sulfur analog.