Synthesis of certain 1,2,4-triazole nucleoside derivatives

Article abstract of DOI:10.1002/jhet.5570270447

The syntheses of 3-amino-4-methyl-l-(β-D-ribofuranosyl)-1,2,4-triazolin-5-one (8a) and its 2'-deoxy analog 8b as well as 5-amino-2-methyl-l-β-D-ribofuranosyl)-1,2,4-triazolin-3-one (12) have been accomplished. Compounds 8a and 8b were synthesized via glycosylation of 3-bromo-5-nitro-1,2,4-triazole which was followed by replacement in three steps of the 3-bromo function to yield 3-nitro-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-1,2,4-triazolin- 5-one (4a) and its 2'-deoxy analog 4b. Compounds 4a and 4b were methylated at N², hydrogenated and deblocked to give 3-amino-4-methyl-l-(β-D-ribofuranosyl)-1,2,4-triazolin-5-one (8a) and the 2'-deoxy analog 8b. Compound 12 was synthesized by glycosylation of 3-amino-l-methyl-1,2,4-triazolin-5(2H)-one (10). The structures of 8b and 12 were confirmed by single crystal X-ray diffraction analysis.