SYNTHESIS OF CERTAIN 1,2,4-TRIAZOLE NUCLEOSIDE DERIVATIVES

The syntheses of 3‐amino‐4‐methyl‐1‐(β‐D‐ribofuranosyl)‐1,2,4‐triazolin‐5‐one (8a) and its 2′‐deoxy analog 8b as well as 5‐amino‐2‐methyl‐1‐(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‐1‐(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‐1‐methyl‐1,2,4‐triazolin‐5(2H)‐one (10). The structures of 8b and 12 were confirmed by single crystal X‐ray diffraction analysis. Copyright © 1990 Journal of Heterocyclic Chemistry