Synthesis of nitrogen-bridged purine-like C-nucleosides from ethyl 2,5-anhydro-6-O-benzoyl-d-allonodithioate

Abstract Ethyl 2,5-anhydro-6- O -benzoyl- d -allonodithioate ( 1 ) was coupled with aminomethyl- and hydrazino-azines to afford the title compounds. Specifically, 1 was coupled with 2-(aminomethyl)pyridine to afford 3-β- d -ribofuranosylimidazolo-[1,5- a ]pyridine, with 2-hydrazinopyrazine to yield 3-β- d -ribofuranosyl-1,2,4-triazolo[4,3- a ]pyrazine, and with 2-hydrazinopyrimidine to form a 3-substituted 1,2,4-triazolo[4,3- a ]pyrimidine which underwent a Dimroth rearrangement to yield 2-β- d -ribofuranosyl-1,2,4-triazolo[1,5- a ]pyrimidine. Finally, compound 1 was coupled with 2-hydrazino-4-hydroxy-6-methylpyrimidine to yield 7-methyl-3-β- d -ribofuranosyl- 1,2,4-triazolo[4,3- a ]-5(8 H )-pyrimidone.