Abstract
2-(Arylamino)pyrimidin-4-ones were synthesized, silylated, and condensed with l,2,3,5-tetra-O-acetyl-beta-D-ribofuranoside to afford the corresponding N-2-aryl protected isocytidines. Deprotection of the acetylated isocytidines using saturated NH3 in MeOH solution gave 1-(beta-D-ribofuranosyl)-2-(arylamino)-4-pyrimidinones. Methyl 2-deoxy-3,5-di-O-toluyl-alpha/beta-D-ribofuranoside was prepared and condensed with the previously silylated bases to afford the anomeric mixture of protected nucleosides. The pure beta-anomers were synthesized with better yield by treating the sodium salts of N-2-arylisocytosine derivatives with 2-deoxy-3,5-di-O-toluyl-alpha-D-ribofuranosyl chloride. Deprotection of the latter anomers afforded the corresponding free hydroxyl derivatives. The synthesized free nucleosides are under antiviral and oligonucleotide investigations.